Figure 9. Constant current (CC) (dis)charge cycling between  $3.0\mathrm{V}$  and  $4.1\mathrm{V}$  (0.35 C-rate) for an ALD-deposited  $\mathrm{LiCoO_2}$ $(x = 4)$  film on  $\mathrm{Si / TiO_2 / Pt}$ , using  $\mathrm{LiClO_4}$  in ethylene carbonate/diethyl carbonate (EC/DEC 1/1) as liquid electrolyte. (a) (dis)charge of  $\mathrm{LiCoO_2}$ , (b) the derivative of the storage capacity with respect to the electrode potential and (c) the electrochemical storage capacity upon cycling showing data for  $x = 2$  and  $x = 4$ .

Constant current charge and discharge curves of an ALD LiCoO2 film (x = 4) between 3.0 V and 4.1 V versus Li/Li+, plotted as E versus Q. The paper notes an about 12% capacity loss between charge and discharge in this panel.

Differential capacity dQ/dE versus E for the same cycling window, showing a clear charge transfer feature near 3.9 V that the paper associates with LiCoO2.

Capacity versus cycle number comparing x = 2 and x = 4 films, showing higher capacity for x = 4 and fairly stable cycling behavior over the shown cycles, with areal capacity on the left axis and gravimetric capacity on the right axis.

| Q, mAh/g | E (V) vs Li/Li⁺ (Charge) | E (V) vs Li/Li⁺ (Discharge) |
|---|---|---|
| 5 | 3.20 | 3.00 |
| 10 | 3.55 | 3.20 |
| 20 | 3.70 | 3.50 |
| 40 | 3.85 | 3.70 |
| 60 | 3.92 | 3.85 |
| 80 | 4.00 | 3.92 |
| 95 | 4.15 | 4.00 |

| E (V) vs Li/Li⁺ | dQ/dE (mAh/Vg) Charge | dQ/dE (mAh/Vg) Discharge |
|---|---|---|
| 3.2 | 0 | 0 |
| 3.4 | 0 | 0 |
| 3.6 | 0.05 | -0.05 |
| 3.8 | 0.10 | -0.10 |
| 3.9 | 0.35 | -0.40 |
| 3.95 | 0.80 | -0.75 |
| 4.0 | 0.40 | -0.30 |
| 4.05 | 0.20 | -0.15 |

| (Dis)charge cycles | Capacity Co/Li (x)=4 (μAh μm⁻¹cm⁻²) | Capacity Co/Li (x)=4 (mAh/g) | Capacity Co/Li (x)=2 (μAh μm⁻¹cm⁻²) | Capacity Co/Li (x)=2 (mAh/g) |
|---|---|---|---|---|
| 1 | 26 | 95 | 11.5 | 42 |
| 2 | 25.5 | 93 | 11.5 | 42 |
| 3 | 25 | 92 | 11.5 | 42 |
| 5 | 25 | 91 | 11 | 40 |
| 7 | 24.5 | 90 | 11 | 40 |
| 10 | 24.5 | 89 | 10.5 | 38 |
| 12 | 24 | 88 | 10 | 37 |
| 14 | 24 | 88 | 10 | 37 |

Answer:
Voltage window: 3.0 V to 4.1 V versus Li/Li+

Constant current cycling at 0.35 C rate

Liquid electrolyte: LiClO4 in EC/DEC 1/1

Answer: Yes

Answer: The y axis is dQ/dE (differential capacity) and the x axis is E versus Li/Li+.

Answer: A charge transfer reaction at about 3.9 V as expected for LiCoO2.


Figure 10. (Color online) Cyclic voltammetric scans at  $1\mathrm{mV / s}$  of  $60~\mathrm{nm}$  thick TaN and TiN films showing the reaction of the films toward Li ions.

The chart shows a cyclic voltammetric scan for two different materials, TaN (H₂ plasma) and TiN (H₂-N₂ 30:4 plasma), performed at 1 mV/s.

| Potential (V) | Current (µA/cm²) TaN | Current (µA/cm²) TiN |
|---|---|---|
| 0.0 | -9 | -1 |
| 0.5 | -6 | -0.8 |
| 1.0 |  0 | -0.5 |
| 1.5 | 9 | -0.3 |
| 2.0 | 4 | -0.2 |
| 2.5 |  0 | -0.1 |
| 3.0 | 0 | 0 |

Answer: 1 mV/s.

Answer: Both were 60 nm thick.

Answer: 0 to 3 V.

Answer: The TaN films have a much higher current density than TiN, indicating a higher reactivity toward the Li-containing electrolyte.


Figure 2. (Color online) The thickness of the TaN and TiN films as a function of number of ALD cycles. The thicknesses have been determined by in situ spectroscopic ellipsometry.

The line chart shows the relationship between the number of cycles and film thickness for TaN (H₂ plasma) and TiN (H₂-N₂ 30:4 plasma). Both materials exhibit a linear increase in film thickness with increasing cycle count.

| Number of cycles | Film thickness (nm) TaN | Film thickness (nm) TiN |
|---|---|---|
| 0 | 0 | 0 |
| 50 | 2.5 | 2 |
| 100 | 5 | 4 |
| 150 | 7 | 6 |
| 200 | 10 | 8 |
| 250 | 12 | 10 |
| 300 | 14.5 | 12 |

Answer: TaN and TiN.

Answer: 300.

Answer: About 7.5 nm.

Answer: Roughly 14.5 nm.


Figure 3. (Color online) (a) The growth per cycle and (b) the FPP resistivity of TaN and TiN films as a function of the plasma exposure time in the ALD cycle. The lines serve as guides to the eyes.

The figure depicts the growth rate of TiN and TaN films as a function of plasma exposure time, where the growth rate of TiN plateaus after 5 seconds, but the growth rate of TaN keeps increasing after 5 seconds.

The figure depicts the FPP resistivity of the TiN and TaN films as a function of plasma exposure time. The resistivity of TiN is practically constant, but the resistivity of TaN decreases exponentially as a function of plasma exposure time.

| Plasma exposure time (s) | TaN (H₂ plasma) | TiN (H₂-N₂ 30:4 plasma) |
|---|---|---|
| 0 | 0.02 | 0.03 |
| 5 | 0.03 | 0.04 |
| 10 | 0.04 | 0.04 |
| 20 | 0.05 | 0.04 |
| 30 | 0.06 | 0.04 |

| Plasma exposure time (s) | TaN (H₂ plasma) | TiN (H₂-N₂ 30:4 plasma) |
|---|---|---|
| 0 | 3*10^4 | 2*10^2 |
| 5 | 4*10^3 | 2*10^2 |
| 10 | 10^3 | 2*10^2 |
| 30 | 4*10^2 | 10^2 |

Answer: The growth rates for both species as a function of time increase rapidly during the first few seconds of plasma exposure. The growth rate of TiN quickly plateaus after 5 seconds of exposure, whilst the growth rate of TaN keeps increasing steadily, albeit significantly slower than the initial time exposure.

Answer: 0.04 nm/cycle.

Answer: 3*10^4 μΩ cm.

Answer: 10^2 μΩ cm.


Figure 5. (Color online) The sheet resistance at  $150^{\circ}\mathrm{C}$  of the TaN-Si, TiN-Si, Cu-TaN-Si, and Cu-TiN-Si stacks after heating to the anneal temperature indicated at the horizontal axis. The annealing temperature was increased in steps of  $50^{\circ}\mathrm{C}$  up to a maximum temperature of  $700^{\circ}\mathrm{C}$ .

The chart shows the sheet resistance at 150°C for different stack configurations (TaN-Si, TiN-Si, Cu-TaN-Si, Cu-TiN-Si) as a function of temperature.

| Temperature (°C) | Sheet resistance (Ω/□) TaN-Si stack | Sheet resistance (Ω/□) TiN-Si stack | Sheet resistance (Ω/□) Cu-TaN-Si stack | Sheet resistance (Ω/□) Cu-TiN-Si stack |
|---|---|---|---|---|
| 150 | 60 | 10 | 0.2 | 0.1 |
| 200 | 60 | 10 | 0.2 | 0.1 |
| 250 | 60 | 10 | 0.2 | 0.1 |
| 300 | 60 | 10 | 0.2 | 0.1 |
| 350 | 60 | 10 | 0.2 | 0.1 |
| 400 | 60 | 10 | 0.2 | 0.1 |
| 450 | 50 | 10 | 0.2 | 0.1 |
| 500 | 30 | 9 | 0.2 | 0.1 |
| 550 | 20 | 9 | 0.2 | 0.1 |
| 600 | 30 | 9 | 0.2 | 0.1 |
| 650 | 30 | 8 | 1 | 3 |
| 700 | 20 | 7 | 4 |  |

Answer: Around 10 Ω/.

Answer: Around 60 Ω/.

Answer: Around 0.2 Ω/.

Answer: The figure shows that the TaN–Si stack exhibits a noticeable reduction in sheet resistance once the annealing temperature exceeds roughly 400 °C, indicating an annealing-induced improvement in film quality and demonstrating that TaN maintains thermal stability well above its 225 °C deposition temperature. The TiN–Si stack shows a similar but weaker decrease in resistance, consistent with its higher deposition temperature of 400 °C and thus less room for annealing-driven improvements. In contrast, the Cu–TaN–Si and Cu–TiN–Si stacks initially display very low sheet resistances (approximately 0.2 and 0.1 in the units indicated on the plot), dominated by the highly conductive Cu layer. However, once annealed above about 600 °C, both Cu-containing stacks undergo a dramatic increase in sheet resistance. This sudden rise signals failure of the diffusion barrier; in other words, Cu diffuses into the underlying layers at high temperature, degrading the stack and destroying the low-resistance pathway.


Figure 3. (a) Transmittance spectra of a  $100\mathrm{nm}$  CsI film on sapphire and bare sapphire substrate. (b) Tauc plot of the CsI film in panel (a). The CsI film was deposited at  $150^{\circ}\mathrm{C}$ , pulse durations were 1.5 and  $0.5\mathrm{s}$  for Cs and I precursors, respectively, and  $1.0\mathrm{s}$  purge durations.

The figure shows the optical characterization of a 100 nm ALD-grown CsI film. The transmittance spectrum indicates that the CsI film (blue) is highly transparent (>80%) across the visible and near-infrared range (300–1100 nm), closely matching the bare sapphire substrate (black), confirming high optical quality with minimal scattering or defect-related absorption. A sharp decrease in transmittance near 225 nm marks the onset of strong fundamental absorption.

The Tauc plot (𝛼ℎ𝜈)^2 vs. photon energy shows a linear region, whose extrapolation intersects the energy axis at ~5.5 eV, confirming that CsI is a wide-bandgap insulator with a direct optical bandgap of ~5.5 eV.

| Wavelength (nm) | Transmittance (%) | Material |
|----------------|-------------------|------|
| 200            | 79                 | CsI |
| 200            | 0                 | Sapphire |
| 300            | 84                | CsI |
| 300            | 81                | Sapphire |
| 400            | 84               | CsI |
| 400            | 84                | Sapphire |
| 500            | 85                | CsI |
| 500            | 85                | Sapphire |
| 600            | 85                | CsI |
| 600            | 85                | Sapphire |
| 700            | 85                | CsI |
| 700            | 85                | Sapphire |
| 800            | 85                | CsI |
| 800            | 85                | Sapphire |
| 900            | 85               | CsI |
| 900            | 85               | Sapphire |

| hv (eV) | (αhv)^2 (a.u.) |
|----------|-----------------|
| 5.0      | 0               |
| 5.25     | 0               |
| 5.5      | 1E+16           |
| 5.62      | 8E+16            |
| 5.75     | 3.7E+16           |

Answer: The Blue curve would drop significantly below the Black curve (lower transmittance). Impurities typically act as absorbing centers (darkening the film) or scattering sites. If the film were contaminated, it would appear brownish or cloudy rather than clear.

Answer: The critical absorption feature for CsI is at ~225 nm (5.5 eV).  Borosilicate glass is opaque in this UV region (cutoff ~300 nm). If used, the substrate itself would absorb all the UV light before the CsI band edge was reached. The spectrometer would measure the glass cutoff (4.0 eV) instead of the CsI bandgap (5.5 eV), yielding false data.

Answer: The x-intercept indicates a direct band gap of approximately 5.7 eV. This signifies that the CsI film is a wide-band-gap insulator, where a photon with at least 5.7 eV of energy is required to excite an electron from the valence band to the conduction band.

Answer: The high transmittance and sharp cutoff imply it is an excellent solar-blind VUV coating. It would be transparent to wavelengths above its band edge (~220 nm), blocking visible light, while potentially converting shorter VUV photons into detectable electrons via the photoelectric effect, enabling selective VUV sensing.


Figure 6. (a) Transmittance spectra of the samples made by depositing CsI on a sapphire wafer and then depositing  $\mathrm{PbI}_2$  on CsI. Transmittance spectra of saphire and the as-deposited CsI film are shown for reference. Measurement were made from the center of the sample. (b) Digital photographs of selected samples from panel (a). CsI films were deposited at  $150^{\circ}\mathrm{C}$  with 300 cycles. The pulse durations were  $1.5~\mathrm{s}$  for  $\mathrm{Cs(btsa)}$  and  $1.0~\mathrm{s}$  for  $\mathrm{SnI_4}$  and purge durations were  $1.0~\mathrm{s}$ . In the  $\mathrm{PbI}_2$  deposition, the durations of the precursor pulses were 0.8 and  $2.0~\mathrm{s}$  for  $\mathrm{Pb(btsa)}_2$  and  $\mathrm{SnI_4}$ , respectively, whereas purge durations were  $1.0~\mathrm{s}$ . The diameter of the sapphire wafers was  $5.08~\mathrm{cm}$ .

The figure illustrates the solid-state reaction between CsI and PbI₂ to form perovskite CsPbI₃ as the number of PbI₂ ALD cycles increases. The CsI film is transparent in the visible region with an absorption edge near 225 nm, while PbI₂ shows an absorption edge at approximately 520 nm. With 2000–3000 PbI₂ cycles (the absorption edge shifts to around 700 nm (1.7–1.8 eV), indicating successful formation of the perovskite phase γ-CsPbI₃.At higher doses (3500–4000 cycles), the perovskite absorption feature weakens and the spectrum increasingly resembles pure PbI₂, indicating complete consumption of CsI and accumulation of excess unreacted PbI₂ on the surface.

The image panel shows microscopic images of different materials at various  PbI₂ cycle counts.

| Wavelength (nm) | Transmittance (%) | Sample  |
|----------------:|------------------:|----------------------|
| 250 | 80 | Sapphire |
| 250 | 5  | CsI film |
| 250 | 0  | CsI + 2000 PbI₂ cycles |
| 250 | 0  | CsI + 2500 PbI₂ cycles |
| 250 | 0  | CsI + 3000 PbI₂ cycles |
| 250 | 0  | CsI + 3500 PbI₂ cycles |
| 250 | 0  | CsI + 4000 PbI₂ cycles |
| 250 | 10 | PbI₂ film |
| 300 | 83 | Sapphire |
| 300 | 75 | CsI film |
| 300 | 0  | CsI + 2000 PbI₂ cycles |
| 300 | 0  | CsI + 2500 PbI₂ cycles |
| 300 | 0  | CsI + 3000 PbI₂ cycles |
| 300 | 0  | CsI + 3500 PbI₂ cycles |
| 300 | 0  | CsI + 4000 PbI₂ cycles |
| 300 | 8  | PbI₂ film |
| 350 | 85 | Sapphire |
| 350 | 82 | CsI film |
| 350 | 0  | CsI + 2000 PbI₂ cycles |
| 350 | 0  | CsI + 2500 PbI₂ cycles |
| 350 | 0  | CsI + 3000 PbI₂ cycles |
| 350 | 0  | CsI + 3500 PbI₂ cycles |
| 350 | 5  | CsI + 4000 PbI₂ cycles |
| 350 | 6  | PbI₂ film |
| 400 | 86 | Sapphire |
| 400 | 85 | CsI film |
| 400 | 5  | CsI + 2000 PbI₂ cycles |
| 400 | 5  | CsI + 2500 PbI₂ cycles |
| 400 | 3  | CsI + 3000 PbI₂ cycles |
| 400 | 10 | CsI + 3500 PbI₂ cycles |
| 400 | 5  | CsI + 4000 PbI₂ cycles |
| 400 | 25 | PbI₂ film |
| 450 | 86 | Sapphire |
| 450 | 86 | CsI film |
| 450 | 20 | CsI + 2000 PbI₂ cycles |
| 450 | 10 | CsI + 2500 PbI₂ cycles |
| 450 | 8  | CsI + 3000 PbI₂ cycles |
| 450 | 30 | CsI + 3500 PbI₂ cycles |
| 450 | 40 | CsI + 4000 PbI₂ cycles |
| 450 | 50 | PbI₂ film |
| 500 | 87 | Sapphire |
| 500 | 87 | CsI film |
| 500 | 35 | CsI + 2000 PbI₂ cycles |
| 500 | 25 | CsI + 2500 PbI₂ cycles |
| 500 | 20 | CsI + 3000 PbI₂ cycles |
| 500 | 45 | CsI + 3500 PbI₂ cycles |
| 500 | 60 | CsI + 4000 PbI₂ cycles |
| 500 | 65 | PbI₂ film |
| 600 | 87 | Sapphire |
| 600 | 87 | CsI film |
| 600 | 60 | CsI + 2000 PbI₂ cycles |
| 600 | 55 | CsI + 2500 PbI₂ cycles |
| 600 | 50 | CsI + 3000 PbI₂ cycles |
| 600 | 65 | CsI + 3500 PbI₂ cycles |
| 600 | 80 | CsI + 4000 PbI₂ cycles |
| 600 | 78 | PbI₂ film |
| 700 | 88 | Sapphire |
| 700 | 88 | CsI film |
| 700 | 80 | CsI + 2000 PbI₂ cycles |
| 700 | 75 | CsI + 2500 PbI₂ cycles |
| 700 | 72 | CsI + 3000 PbI₂ cycles |
| 700 | 75 | CsI + 3500 PbI₂ cycles |
| 700 | 84 | CsI + 4000 PbI₂ cycles |
| 700 | 82 | PbI₂ film |
| 900 | 88 | Sapphire |
| 900 | 88 | CsI film |
| 900 | 87 | CsI + 2000 PbI₂ cycles |
| 900 | 85 | CsI + 2500 PbI₂ cycles |
| 900 | 83 | CsI + 3000 PbI₂ cycles |
| 900 | 85 | CsI + 3500 PbI₂ cycles |
| 900 | 88 | CsI + 4000 PbI₂ cycles |
| 900 | 86 | PbI₂ film |

| | Sapphire | CsI & 3000 PbI2 cyc. | CsI & 3500 PbI2 cyc. | CsI & 4000 PbI2 cyc. |
|---|---|---|---|---|
| 1 | Sapphire | CsI & 3000 PbI2 cyc. | CsI & 3500 PbI2 cyc. | CsI & 4000 PbI2 cyc. |

Answer: The appearance of a strong absorption edge at ~700 nm (the film turns black). Pure CsI is transparent, so this darkening confirms the reaction to form CsPbI₃ .

Answer: 3000 cycles (Black) is optimal. It has the strongest absorption. Going to 4000 cycles is worse because the excess PbI₂ layer blocks light (increasing transmittance to 80% at 600 nm), reducing the cell's efficiency.

Answer: Excess Lead Iodide ( PbI₂). The curve shape reverting to match the  PbI₂ reference indicates that all CsI was consumed and unreacted  PbI₂ is now accumulating on top.

Answer: Because it would be transparent to visible light. Without the Perovskite phase (which absorbs < 700 nm), the unreacted bilayer lets sunlight pass right through without generating any electricity.


FIG. 2. (Color online) The imaginary part of the dielectric function  $\epsilon_{2}$  of (a) a conductive, cubic  $\mathrm{TaN}_{x,x\leqslant 1}$  film and (b) a semiconductive  $\mathrm{Ta}_3\mathrm{N}_5$  film as deduced from spectroscopic ellipsometry measurements. The dielectric functions are parametrized using (a) a Drude and two Lorentz oscillators and (b) using two Tauc-Lorentz oscillators. The photon energy ranges from the near infrared  $(0.75 \mathrm{eV})$  to the ultraviolet  $(6.5 \mathrm{eV})$ . The conductive  $\mathrm{TaN}_{x,x\leqslant 1}$  film was deposited using  $10 \mathrm{s} \mathrm{H}_2$  plasma in the ALD cycle, while the  $\mathrm{Ta}_3\mathrm{N}_5$  film was deposited using  $10 \mathrm{s} \mathrm{NH}_3$  plasma.

The figure shows the dielectric function ε₂ as a function of photon energy for different models: Drude Lorentz, Drude, Lorentz 1, and Lorentz 2 for the conductive cubic TaN film

The figure shows the dielectric function ε₂ as a function of photon energy for different models: Tauc-Lorentz, Tauc-Lorentz 1, and Tauc-Lorentz 2 for the semiconductive Ta3N5 film.

| Photon energy (eV) | Drude Lorentz  | Drude | Lorentz 1 | Lorentz 2 |
|---|---|---|---|---|
| 1 | 14 | 8 | 0 | 3 |
| 2 | 9 | 3 | 1 | 5 |
| 3 | 6 | 2 | 2 | 2 |
| 4 | 4 | 1 | 3 | 1 |
| 5 | 5 | 0.5 | 4 | 0.5 |
| 6 | 6 | 0 | 5.5 | 0 |

| Photon energy (eV) | Tauc-Lorentz  | Tauc-Lorentz 1 | Tauc-Lorentz 2 |
|---|---|---|---|
| 1 | 0 | 0 | 0 |
| 2 | 0 | 0 | 0 |
| 3 | 1.5 | 1.5 | 0 |
| 4 | 6 | 5.5 | 0 |
| 5 | 5.8 | 4.5 | 2 |
| 6 | 5 | 2 | 3 |

Answer: The imaginary part of the dielectric function, ε₂.

Answer: A Drude and two Lorentz oscillators.

Answer: Photon energy varies from the near infrared to the ultraviolet.

Answer: Similar to the Tauc-Lorentz 1 model, the dielectric constant of the Tauc-Lorentz model increases until around 4 eV and then decreases. However, the Tauc-Lorentz 2 model shows an increase after 4 eV.


FIG. 3. (Color online) Film thickness as a function of number of remote plasma ALD cycles shown for the growth of cubic  $\mathrm{TaN}_{x,x\leqslant 1}$  (closed symbols) and  $\mathrm{Ta}_3\mathrm{N}_5$  (open symbols) as deduced from in situ spectroscopic ellipsometry measurements. The solid lines are linear fits to the data. The cubic  $\mathrm{TaN}_{x,x\leqslant 1}$  film was deposited using  $10\mathrm{~s~}$  of  $\mathrm{H}_{2}$  plasma in the ALD cycle, while the  $\mathrm{Ta}_3\mathrm{N}_5$  film was deposited using  $10\mathrm{~s~}$  of  $\mathrm{NH}_3$  plasma.

The chart shows the relationship between the number of cycles and film thickness, indicating a linear increase for both TaN x,x⩽1 and Ta3N5.

| Number of cycles | TaN | Ta3N5 |
|------------------|--------------------|--------------------|
| 0                | 0                  | 0                  |
| 100              | 5                  | 6                  |
| 200              | 10                 | 12                  |
| 300              | 15                 | 17                  |
| 400              | 20                 | 15                  |
| 500              | 25                 | 30                  |
| 600              | 30                 | 35                  |
| 700              | 35                 | 40                  |

Answer: Measurements were taken for two films: cubic taN and Ta3N5.

Answer: In accordance with an ALD process, the film thickness increases with the number of cycles for both samples.

Answer: Ta3N5 film is thicker than TaN, because it shows higher film thickness values.

Answer: No


FIG. 7. (Color online) The imaginary part of the dielectric function  $\epsilon_{2}$  of  $\mathrm{TaN}_x$  films deposited under various plasma conditions in the ALD cycle and as determined by in situ spectroscopic ellipsometry: (1)  $30\mathrm{~s~H}_{2}$  plasma  $(x = 0.44)$ , (2)  $10\mathrm{~s~H}_{2}$  plasma  $(x = 0.49)$ , (3)  $5\mathrm{~s~H}_{2} - \mathrm{N}_{2}$  (98:2) plasma  $(x = 1.0)$ , (4)  $10\mathrm{~s~H}_{2} - \mathrm{N}_{2}$  (1:1) plasma  $(x = 1.55)$ , and (5)  $10\mathrm{~s~NH}_{3}$  plasma  $(x = 1.67)$ . The ratio  $x = [\mathrm{N}] / [\mathrm{Ta}]$  of the  $\mathrm{TaN}_x$  films was determined by RBS analysis.

The chart illustrates the dielectric function ε₂ as a function of photon energy (eV). Multiple curves represent different materials and conditions for the TiN ALD cycle.

| Photon energy (eV) | 1 | 2 | 3 | 4 | 5 |
| --- | --- | --- | --- | --- | --- |
| 1 | 30 | 15 | 9 | 1 | 0 |
| 2 | 13 | 10 | 9 | 1 | 0 |
| 3 | 8 | 5 | 5 | 8 | 1 |
| 4 | 7 | 5 | 5 | 10 | 7 |
| 5 | 6 | 5 | 5 | 9 | 7 |
| 6 | 6 | 6 | 5 | 7 | 6 |

Answer: In-situ spectroscopic ellipsometry.

Answer: The dielectric function of sample "1" decreases significantly as the photon energy increases.

Answer: Each film was deposited under different plasma conditions. These conditions could include different exposurre times or plasma gases.

Answer: Photon energies varies from the near infrared to the ultraviolet.


Figure 3. GPC as a function of substrate temperature.

The line chart illustrates the temperature dependence of the atomic layer deposition growth per cycle (GPC) for Y₂O₃ films using Y(EtCp)₂(iPr-amd) with H₂O, O₂ plasma, and H₂O plasma reactants.

| Substrate temperature (°C) | GPC (Å/cycle) | Precursor |
|---|---|---|
| 119 | 0.0 | Y(EtCp)2(iPr-amd) without reactant |
| 151 | 0.0 | Y(EtCp)2(iPr-amd) without reactant |
| 180 | 0.0 | Y(EtCp)2(iPr-amd) without reactant |
| 200 | 0.1 | Y(EtCp)2(iPr-amd) without reactant |
| 220 | 0.1 | Y(EtCp)2(iPr-amd) without reactant |
| 250 | 0.1 | Y(EtCp)2(iPr-amd) without reactant |
| 280 | 0.2 | Y(EtCp)2(iPr-amd) without reactant |
| 300 | 0.3 | Y(EtCp)2(iPr-amd) without reactant |
| 320 | 0.5 | Y(EtCp)2(iPr-amd) without reactant |
| 350 | 0.6 | Y(EtCp)2(iPr-amd) without reactant |
| 380 | 0.8 | Y(EtCp)2(iPr-amd) without reactant |
| 120 | 0.6 | H2O |
| 149 | 0.7 | H2O |
| 179 | 0.8 | H2O |
| 199 | 0.8 | H2O |
| 220 | 0.8 | H2O |
| 250 | 0.8 | H2O |
| 279 | 0.9 | H2O |
| 300 | 1.0 | H2O |
| 320 | 1.1 | H2O |
| 349 | 1.3 | H2O |
| 380 | 1.4 | H2O |
| 120 | 0.7 | O2 plasma |
| 149 | 0.8 | O2 plasma |
| 180 | 0.8 | O2 plasma |
| 200 | 0.9 | O2 plasma |
| 220 | 0.9 | O2 plasma |
| 251 | 0.9 | O2 plasma |
| 279 | 1.0 | O2 plasma |
| 298 | 1.2 | O2 plasma |
| 319 | 1.2 | O2 plasma |
| 349 | 1.4 | O2 plasma |
| 380 | 1.5 | O2 plasma |
| 120 | 0.8 | H2O plasma |
| 149 | 1.0 | H2O plasma |
| 180 | 1.0 | H2O plasma |
| 201 | 1.1 | H2O plasma |
| 220 | 1.1 | H2O plasma |
| 250 | 1.1 | H2O plasma |
| 280 | 1.2 | H2O plasma |
| 300 | 1.3 | H2O plasma |
| 320 | 1.4 | H2O plasma |
| 350 | 1.6 | H2O plasma |
| 381 | 1.7 | H2O plasma |

Answer: 150 - 300 °C.

Answer: 150 - 300 °C.

Answer: Yes, there is clear evidence of thermal decomposition of the yttrium precursor above 300°C. The growth rate for the precursor without any reactant (gray line) begins to rise significantly above this temperature. this indicates self-deposition.

Answer: Above 300°C, GPC rises for all tested processes. The systematic increase is most likely caused by the  thermal decomposition of the yttrium precursor molecules. This  disrupts the self-limiting surface reactions required for ALD, leading to uncontrolled material deposition. This is confirmed by the significant growth observed when pulsing the yttrium precursor without any co-reactant.


Figure 4. Selected  $\theta_{\mathrm{Kerr}}$  vs field hysteresis loops for (a)  $\mathrm{ZnO}$ ; (b) oxygen-deficient  $\mathrm{ZnO}$ ; and (c)  $\mathrm{Ni - }$ , (d)  $\mathrm{Co - }$ , and (e) Fe-doped  $\mathrm{ZnO}$  layers. The insets show example curves with large hysteresis and Kerr angle values.

A line chart showing the relationship between magnetic field strength and Kerr rotation angle for undoped ZnO.

A line chart showing the relationship between magnetic field strength and Kerr rotation angle for oxygen-deficient ZnO.

A line chart showing the relationship between magnetic field strength and Kerr rotation angle for  Ni doped ZnO

A line chart showing the relationship between magnetic field strength and Kerr rotation angle for Co doiped ZnO.

A line chart showing the relationship between magnetic field strength and Kerr rotation angle for Fe doped ZnO.

| Magnetic field (Oe) | θ_Kerr (mdeg) |
|---|---|
|-4000 |-15 |
|-3000 |-10 |
|-2000 |-5 |
|-1000 |0 |
|0 |0 |
|1000 |5 |
|2000 |10 |
|3000 |15 |
|4000 |20 |

| Magnetic field (Oe) | θ_Kerr (mdeg) |
|---|---|
|-4000 |-100 |
|-3000 |-80 |
|-2000 |-60 |
|-1000 |-40 |
|0 |0 |
|1000 |40 |
|2000 |60 |
|3000 |80 |
|4000 |100 |

| Magnetic field (Oe) | θ_Kerr (mdeg) |
|---|---|
|-4000 |-60 |
|-3000 |-50 |
|-2000 |-40 |
|-1000 |-30 |
|0 |0 |
|1000 |30 |
|2000 |40 |
|3000 |50 |
|4000 |60 |

| Magnetic field (Oe) | θ_Kerr (mdeg) |
|---|---|
|-4000 |-90 |
|-3000 |-70 |
|-2000 |-50 |
|-1000 |-30 |
|0 |0 |
|1000 |30 |
|2000 |50 |
|3000 |70 |
|4000 |90 |

Answer: Yes

Answer:
1. For undoped ZnO, θ_Kerr varies from ~-15 mdeg to + 15 mdeg
2. For oxygen-deficient ZnO,  θ_Kerr varies from ~-15 mdeg to + 15 mdeg
3. For Ni-doped ZnO,  θ_Kerr varies from ~-100 mdeg to + 100 mdeg
4. For Co-doped ZnO,   θ_Kerr varies from ~-60 mdeg to + 60 mdeg
5. For Fe-doped ZnO,  θ_Kerr varies from ~-90 mdeg to + 90 mdeg

Answer: Inhomogeneity is observed for both undoped and TM-doped ZnO layers. The observed complex micro MOKE (diffracted and asymmetrical) hysteresis loops, particularly for the TM-doped samples, reveal the variations and non-uniformity of the MO response. As is seen, these variations are significant in the case of TM-doped layers and for a certain fraction of the measurements shown in the insets with broad hysteresis contours, and θKerr can reach significant values at the maximum applied field.

Answer: MOKE stands for magneto optic kerr effect,


Fig. 1. Mass sensor signal as a function of time recorded at temperatures of  $100$  and  $300^{\circ}\mathrm{C}$  during a single ALD cycle. Mass sensor was covered with a buffer layer deposited at  $300^{\circ}\mathrm{C}$ .

Real-time mass sensor signal vs. time during a single ALD cycle at growth temperatures of 100C and 300C. The plot defines the specific mass changes: $\Delta m_1$ (gain from TiCl_4 pulse), $\Delta m_2$ (loss during purge/reaction), $\Delta m_2'$ (initial desorption), and $\Delta m_0$ (net mass increment per cycle).

| Time (s) | Event | Signal 300°C (Top) | Signal 100°C (Bottom) |
|---|---|---|---|
| 10 | Start TiCl4 Pulse | ~0 | ~0 |
| 12 | End TiCl4 Rise (Δm1) | ~70 | ~60 |
| 20 | End TiCl4 Pulse | ~70 | ~60 |
| 25 | Start H2O Pulse | ~65 | ~55 |
| 26 | Drop (Δm2') | ~35 | ~35 |
| 30 | End H2O Pulse | ~35 | ~35 |
| 40 | Final Level (Δm0) | ~35 | ~35 |

Answer:
1.300°C
, 2. 100°C

Answer: Yes, the vertical step height labeled Δm1 is clearly larger in the top trace (300°C).

Answer: During the TiCl₄ pulse, the top trace shows a sharp step increase labeled Δm₁, followed by a plateau while the pulse continues. Around the H₂O pulse, the signal decreases, with the drop region annotated by Δm₂ and Δm₂′. The trace then settles to a lower plateau and finishes the cycle at a baseline shifted upward from the start, labeled Δm₀. Overall, it’s a step-up (TiCl₄) then step-down (H₂O-related) response with a nonzero net offset.

Answer: TiCl4


FIG.4. Growth profiles for a  $200ms$  20 mTorr precursor dose for different values of the reaction probability  $\beta_{10}$  Higher reaction probabilities lead to steeper growth profiles.

The chart shows the surface coverage of a material along the axial position. Different lines represent different reaction probabilities (β10).

| Axial position (m) | Coverage (β10 = 0.0001) | Coverage (β10 = 0.0002) | Coverage (β10 = 0.0005 | Coverage (β10 = 0.001) | Coverage (β10 = 0.002) | Coverage (β10 = 0.005) | Coverage (β10 = 0.01) | Coverage (β10 = 0.02) |
|---|---|---|---|---|---|---|---|---|
| 0.0 | 0.1 | 0.15 | 0.3 | 0.5 | 0.75 | 0.95 | 1 | 1 |
| 0.1 | 0.1 | 0.15 | 0.3 | 0.45 | 0.6 | 0.85 | 1 | 1 |
| 0.2 | 0.1 | 0.15 | 0.3 | 0.4 | 0.5 | 0.6 | 0.75 | 0.9 |
| 0.3 | 0.1 | 0.15 | 0.25 | 0.35 | 0.4 | 0.4 | 0.2 | 0.175 |
| 0.4 | 0.1 | 0.15 | 0.25 | 0.3 | 0.3 | 0.2 | 0.1 | 0.05 |

Answer: 200 ms.

Answer: 20 mTorr.

Answer: The reaction probability (β10).

Answer: Figure 4 shows that the reaction probability β₁₀ strongly controls how rapidly surface coverage develops along the reactor, but its effect depends on whether the process is transport-limited or reaction-limited. At relatively high reaction probabilities, decreasing β₁₀ reduces the steepness of the unsaturated growth profile, leading to a more gradual increase in surface coverage without a proportional decrease in the total mass uptake; in this regime, the deposited mass is primarily redistributed spatially within the reactor rather than reduced overall. As β₁₀ is lowered further, the system transitions into a reaction-limited regime, where surface reactions become the bottleneck and the surface coverage decreases directly in proportion to β₁₀.

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/11/Angel Yanguas-Gil et al.pdf


FIG. 10. Reactor growth profiles for a soft-saturating self-limited model with two components (a)  $\beta_{1b} = 10^{-2}$  and  $\beta_{1b} = 10^{-3}$  and (b)  $\beta_{1b} = 10^{-2}$  and  $\beta_{1b} = 10^{-4}$ . All profiles correspond to the same unsaturated dose time of  $0.2 \text{s}$  for an average precursor pressure at the inlet of 50 mTorr. (c) Surface coverage for increasing dose times using (b) conditions.

The figure shows the reactor growth profiles for a soft-saturating self-limited model with two components, with β_1a = 10^-2 and β_1b = 10^-3.

The figure shows the reactor growth profiles for a soft-saturating self-limited model with two components, with β_1a = 10^-2 and β_1b = 10^-4.

The figure shows the reactor growth profiles with the same conditions as (b), but with four different dose times (t_d).

| Axial position (m) | f₂ = 0 | f₂ = 0.1 | f₂ = 0.2 | f₂ = 0.4 | f₂ = 0.6 | f₂ = 0.8 | f₂ = 1 |
|---|---|---|---|---|---|---|---|
| 0.00 | 1.00 | 0.95 | 0.90 | 0.80 | 0.65 | 0.55 | 0.45 |
| 0.10 | 0.98 | 0.92 | 0.88 | 0.75 | 0.60 | 0.50 | 0.40 |
| 0.20 | 0.85 | 0.80 | 0.75 | 0.65 | 0.55 | 0.45 | 0.35 |
| 0.30 | 0.30 | 0.35 | 0.45 | 0.55 | 0.50 | 0.40 | 0.30 |
| 0.40 | 0.05 | 0.10 | 0.15 | 0.30 | 0.35 | 0.30 | 0.25 |

| Axial position (m) | f₂ = 0 | f₂ = 0.1 | f₂ = 0.2 | f₂ = 0.4 | f₂ = 0.6 | f₂ = 0.8 | f₂ = 1 |
|---|---|---|---|---|---|---|---|
| 0.00 | 1.00 | 0.95 | 0.85 | 0.65 | 0.45 | 0.25 | 0.08 |
| 0.10 | 0.98 | 0.92 | 0.82 | 0.62 | 0.44 | 0.25 | 0.08 |
| 0.20 | 0.90 | 0.85 | 0.75 | 0.60 | 0.43 | 0.25 | 0.08 |
| 0.30 | 0.35 | 0.45 | 0.55 | 0.50 | 0.42 | 0.25 | 0.08 |
| 0.40 | 0.08 | 0.12 | 0.20 | 0.40 | 0.40 | 0.25 | 0.08 |

| Axial position (m) | t_d = 0.2 s | t_d = 0.3 s | t_d = 0.5 s | t_d = 1.0 s |
|---|---|---|---|---|
| 0.00 | 0.90 | 0.92 | 0.93 | 0.94 |
| 0.10 | 0.88 | 0.91 | 0.92 | 0.94 |
| 0.20 | 0.75 | 0.90 | 0.92 | 0.94 |
| 0.30 | 0.40 | 0.88 | 0.92 | 0.94 |
| 0.40 | 0.12 | 0.70 | 0.92 | 0.94 |

Answer: Roughly 0.9.

Answer: 50 mTorr.

Answer: 0.2 seconds.

Answer: Figure 10 shows that the presence and relative contribution of a slow self-limited reaction component can substantially alter growth profiles and lead to apparent saturation behaviour that is not fully representative of true surface saturation. When both fast and slow components have relatively high reaction probabilities, increasing the fraction of the slow component produces a gradual transition from a steep, step-like saturation profile to a more gently varying, nearly linear axial coverage profile. When the reaction probability of the slow component is reduced by two orders of magnitude, profiles near the reactor inlet can exhibit a plateau characteristic of saturated growth even though the absolute surface coverage remains well below full saturation. Increasing the dose time in this regime further accentuates this effect: beyond a certain dose duration, the process appears saturated, yet the slow component continues to evolve and yields a small but measurable increase in surface coverage.


FIG. 13. Coverage profiles in the presence of competitive adsorption by reaction by-products. (a) Precursor coverage profile for a process characterized by  $\beta_{10} = 10^{-2}$  and  $p_0 = 50$  mTorr. (b) By-products coverage profiles for the same conditions used in (a). Note how  $\Theta +\Theta_{bp} = 1$  indicating that the process is fully saturated. (c) Impact of precursor partial pressure for a process characterized by  $\beta_{10} = 10^{-2}$  and  $\beta_{bp0} = 10^{-3}$

The figure shows the precursor coverage (Precursor cov.) against axial position (m) for different values of $\beta_{bp}$.

The figure shows the byproduct coverage (Byproduct cov.) against axial position (m) for different values of $\beta_{bp}$.

The figure shows the precursor coverage against the axial position for different values of precursor partial pressure.

| Axial position (m) | Precursor cov. $\beta_{bp}$ = 0 | Precursor cov. $\beta_{bp}$ = 0.0001 | Precursor cov. $\beta_{bp}$ = 0.001 | Precursor cov. $\beta_{bp}$ = 0.01 |
|---|---|---|---|---|
| 0.0 | 1.00 | 1.00 | 1.00 | 0.85 |
| 0.1 | 1.00 | 1.00 | 0.95 | 0.75 |
| 0.2 | 1.00 | 1.00 | 0.90 | 0.65 |
| 0.3 | 1.00 | 1.00 | 0.85 | 0.60 |
| 0.4 | 1.00 | 1.00 | 0.80 | 0.50 |

| Axial position (m) | Byproduct cov. $\beta_{bp}$ = 0 | Byproduct cov. $\beta_{bp}$ = 0.0001 | Byproduct cov. $\beta_{bp}$ = 0.001 | Byproduct cov. $\beta_{bp}$ = 0.01 |
|---|---|---|---|---|
| 0.0 | 0.00 | 0.00 | 0.00 | 0.15 |
| 0.1 | 0.00 | 0.00 | 0.05 | 0.25 |
| 0.2 | 0.00 | 0.00 | 0.10 | 0.35 |
| 0.3 | 0.00 | 0.00 | 0.15 | 0.40 |
| 0.4 | 0.00 | 0.00 | 0.20 | 0.50 |

| Axial position (m) | Precursor cov. 100 mTorr | Precursor cov. 50 mTorr | Precursor cov. 25 mTorr |
|---|---|---|---|
| 0.0 | 0.98 | 0.98 | 0.98 |
| 0.1 | 0.95 | 0.95 | 0.95 |
| 0.2 | 0.93 | 0.92 | 0.90 |
| 0.3 | 0.93 | 0.89 | 0.85 |
| 0.4 | 0.90 | 0.85 | 0.80 |

Answer: Increasing the precursor pressure reduces the impact of by-product adsorption, leading to weaker axial coverage gradients.

Answer: 50 mTorr.

Answer: β₁₀ = 10⁻².

Answer: Increasing the by-product reaction probability introduces progressively stronger axial gradients in the precursor surface coverage, even though the process is saturated, because adsorbed by-products occupy surface sites and reduce the available precursor coverage according to Θ = 1 − Θ_bp.


Fig. 6. Predicted energies for the second chlorine loss pathways via hydrolysis (R3a and R3b). The zero is the sum energy of the products of R1a/R1b and water.

The figure illustrates a potential energy diagram plotting the energy changes  (ΔE)  for two reaction pathways (R3a and R3b). The chart compares the pathways through their chemisorption states (CS),  transition states (TS) and intermediate physisorption states (PS), revealing that pathway R3a is energetically more favorable than R3b.

|  Reaction coordinate, a.u.| Species Label | ΔE, kJ/mol |
| --- | --- | --- |
| 1 | CS(R3a) | -64.5 |
| 2 | TS(R3a) | 2.2 |
| 3 | PS(R3a) | -20.4 |
| 4  | Product(R3a) | -11.1 |
| 1 | CS(R3b) | -59.7 |
| 2 | TS(R3b) | 10.1 |
| 3 | PS(R3b) | -12.4 |
| 4 | Product(R3b) | 11.5 |

Answer: R3a.

Answer: Pathway R3a proceeds faster than pathway R3b. This conclusion is supported by the lower potential energy barrier found at the transition state (TS). The diagram shows that R3a has a barrier at only 2.2 kJ/mol, whereas R3b faces a higher barrier of 10.1 kJ/mol.

Answer: Product(R3a) is the more stable product.

Answer: Pathway R3b is endothermic.

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/15/Chengxing Cui et al.pdf


Figure 14: (a) Blue line shows the total density profiles at 0 ALD cycles, red for four ALD cycles, and green for eight ALD cycles with respect to the Z-direction distance of the  $\mathsf{Al}_2\mathsf{O}_3$  film at  $300^{\circ}C$  [186]. (b) The number density profiles for oxygen (blue), aluminium (green), and hydrogen (red) as a function of the Z-direction distance of  $\mathsf{Al}_2\mathsf{O}_3$  film at  $300^{\circ}C$  [186].

The line graph shows the density profiles of an Al₂O₃ film along its thickness (Z-direction) at three stages of ALD: 0 cycles (blue), 4 cycles (red), and 8 cycles (green), all at 300°C. The plot reveals how film density evolves with ALD cycles

The graph shows the number density profiles (in atoms/nm³) for Oxygen (O - blue), Aluminum (Al - green), and Hydrogen (H - red) atoms across the thickness (Z-direction) of an Al₂O₃ film deposited at 300°C. The profiles reveal the layered atomic composition of the film: Oxygen and Aluminum densities peak in the main film region (~8–15 Å) where the Al₂O₃ matrix forms, while Hydrogen density is prominent at the film's interfaces, likely indicating surface hydroxyl groups (-OH) or precursor ligands.

| Z (Å) | L0 density (g/cm³) | L4 density (g/cm³) | L8 density (g/cm³) |
| --- | --- | --- | --- |
| 3.0 | 1.10 | 1.10 | 1.10 |
| 4.0 | 0.55 | 0.56 | 0.56 |
| 5.0 | 0.56 | 0.56 | 0.56 |
| 6.0 | 0.80 | 0.85 | 0.85 |
| 7.0 | 0.55 | 0.70 | 0.75 |
| 8.0 | 0.25 | 0.50 | 0.65 |
| 9.0 | 0.05 | 0.30 | 0.55 |
| 10.0 | 0.00 | 0.15 | 0.45 |
| 11.0 | 0.00 | 0.05 | 0.35 |
| 12.0 | 0.00 | 0.02 | 0.28 |
| 13.0 | 0.00 | 0.00 | 0.20 |
| 14.0 | 0.00 | 0.00 | 0.12 |
| 15.0 | 0.00 | 0.00 | 0.05 |
| 16.0 | 0.00 | 0.00 | 0.02 |
| 17.0 | 0.00 | 0.00 | 0.00 |

| Z (Å) | O Number density (nm⁻³) | Al Number density (nm⁻³) | H Number density (nm⁻³) |
| --- | --- | --- | --- |
| 3.0 | 13.7 | 17.0 | 0.3 |
| 4.0 | 14.3 | 3.7 | 0.4 |
| 5.0 | 9.4 | 7.7 | 1.3 |
| 6.0 | 15.0 | 9.9 | 1.4 |
| 7.0 | 12.7 | 7.6 | 2.0 |
| 8.0 | 10.1 | 5.8 | 3.04 |
| 9.0 | 8.0 | 3.4 | 3.9 |
| 10.0 | 4.2 | 1.7 | 3.7 |
| 11.0 | 2.6 | 0.76 | 2.4 |
| 12.0 | 1.1 | 0.13 | 1.3 |
| 13.0 | 0.42 | 0.02 | 0.6 |
| 14.0 | 0.10 | 0.00 | 0.05 |
| 15.0 | 0.00 | 0.00 | 0.00 |
| 16.0 | 0.00 | 0.00 | 0.00 |
| 17.0 | 0.00 | 0.00 | 0.00 |

Answer:
An oxygen-enriched surface region is indicated by the sharp O peak at the smallest Z, consistent with terminal oxygen or hydroxyl groups at the outer surface.

A subsurface region where Al and O peaks overlap suggests a more stoichiometric Al₂O₃ network with coordinated Al–O polyhedra.

A broader hydrogen profile peaking slightly beyond the main Al region implies surface and near-surface hydroxylation, with hydrogen bonded to oxygen at or just beneath the interface.

The decay of all three profiles to near zero at larger Z indicates that the film terminates within the plotted range, with negligible atomic population beyond about 13–14 Å.

Answer: Low bulk hydrogen indicates a pure Al₂O₃ lattice with minimal impurity-based charge traps. Hydrogen in oxides can create electronic defects that increase leakage current and reduce dielectric reliability. Therefore, its confinement to the interfaces suggests the functional bulk of the film has high electrical quality.

Answer:
Initial substrate interface (0 cycles, blue).

, Film nucleation and early growth (4 cycles, red).

, Thickening and development of a uniform bulk region (8 cycles, green).

Answer: The central density is lower and less uniform at 4 cycles, but reaches a stable, high plateau (~1.0 g/cm³) at 8 cycles. The trade-off is between process speed (fewer cycles) and material quality (uniform, dense film). Achieving device-grade films requires more cycles to move past the non-uniform interfacial growth phase.

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/17/David Sibanda et al.pdf


Figure 21: Heat capacity values  $(C_{\mathrm{v}})$  of various size FNPs [161].

The multiple line chart represents the Specific heat capacity (Cv) against temperature for various iron nanoparticles (FNP) with the dimensions (2 nm, 2.5 nm, 3.0 nm, 3.5 nm, and 4.0 nm). Sharp peaks were observed at specific temperatures indicating melting points of the respective particles. This graph illustrates the melting point depression phenomenon, where the melting temperature drops significantly (from 2100 K to 1525 K) as the nanoparticle diameter decreases from 4.0 nm to 2.0 nm. It confirms that smaller particles are thermodynamically less stable and undergo phase transitions at lower thermal energies compared to larger ones.

| Temperature (K) | 2 nm | 2.5 nm | 3.0 nm | 3.5 nm | 4.0 nm |
|---|---|---|---|---|---|
| 200 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 400 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 600 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 800 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 1000 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 1200 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 1400 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 1525 | 0.4| 0.0 | 0.0 | 0.0 | 0.0 |
| 1600 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 1775 | 0.0 | 0.8 | 0.0 | 0.0 | 0.0 |
| 1800 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 1925 | 0.0 | 0.0 | 0.9 | 0.0 | 0.0 |
| 2000 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 2050 | 0.0 | 0.0 | 0.0 | 0.6 | 0.0 |
| 2100 | 0.0 | 0.0 | 0.0 | 0.0 | 1.6 |
| 2200 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 2400 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |

Answer: This implies the catalyst must operate at a significantly lower temperature than expected for bulk iron to prevent deactivation. If the process temperature approaches the depressed melting point of the nanoparticles, they will become mobile and rapidly sinter, destroying the high-surface-area catalyst structure. The operational window is constrained by this size-dependent thermal instability.

Answer: Larger nanoparticles have a higher melting point. The sharp Cv peak shifts to higher temperatures as diameter increases from 2 nm to 4 nm. The cause is the surface-to-volume ratio: smaller particles have a larger fraction of surface atoms with lower coordination and higher energy, making the entire lattice less stable and melting at a lower temperature.

Answer:
2 nm
, 2.5 nm
, 3.0 nm
, 3.5 nm
, 4.0 nm

Answer: For computational efficiency in screening, the potential energy method is often preferred. It requires fewer data points to identify the trend break and avoids the extra step of calculating the derivative, saving time for each simulation run.


Fig. 4. Plot of the changes in selected bond lengths and distances (Hf-Cl, Hf-O, O-H and Cl-H) along the calculated IRC for the elimination of HCl from  $\mathrm{Si(OH)_3 - OH - HfCl_4}$  complex. The adsorbed complex is on the left, products are on the right, and the TS is set to  $S = 0$  amu $^{1 / 2}$  bohr.

The line chart shows bond distances (Å) against S((amu)^{1/2}bohr), with four distinct bond types: Hf-Cl, Hf-O, O-H, and Cl-H. Hf-Cl shows a slight increase as the S value increases, while H-O and Cl-H decrease. On the other hand, O-H increases above an S value of -0.5.

| S((amu)^{1/2}bohr) | Hf-Cl | Hf-O | O-H | Cl-H |
|---|---|---|---|---|
|-2.5 | 2.7 | 2.1 | 1.0 | 2.0 |
|-2.0 | 2.7 | 2.1 | 1.0 | 1.9 |
|-1.5 | 2.7 | 2.1 | 1.0 | 1.9 |
|-1.0 | 2.7 | 2.1 | 1.0 | 1.8 |
|-0.5 | 2.8 | 2.1 | 1.1 | 1.7 |
|0.0 | 2.8 | 2.1 | 1.4 | 1.5 |
|0.5 | 2.8 | 2.1 | 1.6 | 1.4 |
|1.0 | 2.8 | 2.0 | 1.7 | 1.3 |
|1.5 | 2.8 | 2.0 | 1.9 | 1.3 |
|2.0 | 2.8 | 2.0 | 2.0 | 1.3 |
|2.5 | 2.9 | 2.0 | 2.1 | 1.3 |

Answer: Changes in bond lenghts are closely related to the transition state (TS).

Answer: As the S value increases from -2.5 to 2.5, the bond distance decreases for Hf-O and Cl-H, and increases for Hf-Cl and O-H.

Answer: The Hf-Cl bond has the highest bond distance values close to 2.7 Å.

Answer: Yes

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/2/Jie Ren et al.pdf


Figure 4. ALD simulations. (A) Height of film growth per cycle and (B) roughness per cycle. Present results compared to Hu et al. The range of growth per cycle commonly observed experimentally is highlighted in yellow.

The line chart shows the film growth per ALD cycle in Å for two studies,  comparing the present study simulation (blue) with the results from Hu et al (red) over 12 cycles. The yellow band marks the experimentally reported growth range (~0.9–1.1 Å/cycle).

The line chart displays the surface roughness  in Å vs. cycle number for two studies, 'Present Study' and 'Hu et al.', over 12 cycles. The roughness from the present study is less rough.

| Cycle | Growth per cycle, Å : Present Study | Growth per cycle, Å: Hu et al. |
| --- | --- | --- |
| 1 | 1.04 | 0.49 |
| 2 | 0.88 | 0.48 |
| 3 | 0.83 | 0.54 |
| 4 | 0.89 | 0.38 |
| 5 | 1.06 | 0.48 |
| 6 | 0.76 | 0.59 |
| 7 | 1.17 | 0.68 |
| 8 | 1.17 | 0.46 |
| 9 | 1.00 | 0.49 |
| 10 | 1.07 | 0.46 |
| 11 | 1.19 | 0.57 |
| 12 | 0.97 | 0.45 |

| Cycle | Surface Roughness, Å: Present Study | Surface Roughness, Å: Hu et al. |
| --- | --- | --- |
| 1 | 0.78 | 1.4 |
| 2 | 1.13 | 1.5 |
| 3 | 1.28 | 1.56; 1.66 |
| 4 | 1.31 | 1.73 |
| 5 | 1.44 | 1.80 |
| 6 | 1.33 | 2.0 |
| 7 | 1.35 | 2.0 |
| 8 | 1.42 | 1.89 |
| 9 | 1.44 | 1.89 |
| 10 | 1.36 | 1.70 |
| 11 | 1.51 | 1.68 |
| 12 | 1.58 | 1.65 |

Answer: Present study (the values are better aligned with experimental ones, shown as yellow band).

Answer: The present study shows higher cycle-to-cycle variability. You can see it from the spread of values: for the present study it ranges from 0.76 Å/cycle (cycle 6) up to 1.19 Å/cycle (cycle 11), a spread of about 0.43 Å/cycle. Hu et al. ranges from 0.38 Å/cycle (cycle 4) to 0.68 Å/cycle (cycle 7), a smaller spread of about 0.30 Å/cycle. From one cycle to the next, the present study has a big jump from 0.76 (cycle 6) to 1.17 (cycle 7) (≈ +0.41), whereas the largest step change in Hu et al. is smaller (e.g., 0.68 → 0.46, ≈- 0.22).  So overall, the values fluctuate more in the present study.

Answer: Present study (the values for roughness are generally lower than in the study of Hu et al.).

Answer: They converge overall (the gap between the two data series decreases).

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/25/Kristopher S. Brown et al.pdf


Figure 6. Predicted and measured alumina ALD coating growths on an alumina (blue) and silica (red) surface. Predictions are depicted by squares and dotted lines. Measurements of Al added on silica $^{47}$  are depicted by red circles and solid lines. Experimental values for Al added over alumina (blue circles and solid lines) inferred from Puurunen's empirical model, $^{45,46}$  which related the number of Al atoms added to surface OH coverage.

The chart shows the number of Al atoms added per unit area (Al/nm²) over cycles for both Al2O3 experiment and model, and SiO2 experiment and model. The Al2O3 experiment and model exhibit a more similar trend, while the SiO2 experiment and model deviate more from each other.

| Cycle | Al2O3 Experiment | SiO2 Experiment | Al2O3 Model | SiO2 Model |
|---|---|---|---|---|
| 1 | 2.5 | 4.5 | 2.8 | 2.4 |
| 2 | 3.2 | 2.4 | 3.4 | 2.4 |
| 3 | 3.4 | 2.7 | 3.2 | 2.1 |
| 4 | 3.2 |- | 3.4 | 2.4 |
| 5 | 3.6 | - | 3.9 | 2.6 |
| 6 | 3.3 | 2.9 | 3.7 | 2.5 |
| 7 | 3.3 | - | 3.7 | 2.7 |
| 8 | 3.4 | 3.2 | 4.1 | 2.9 |
| 9 | 3.4 | - | 3.9 | 3.0 |
| 10 | 3.3 | - | 3.9 | 3.1 |
| 11 | - | 3.8 | - | - |

Answer: Al2O3 model generally overestimates the predicted values of added Al atoms.

Answer: SiO2 model generally underestimates the predicted values of added Al atoms.

Answer: No

Answer: Considering only the experimental data from cycles 1–3, SiO₂ has the greater total Al atoms deposited per area. Even though its rate drops in cycles 2 and 3, the  initial deposition of 4.5 Al/nm² in Cycle 1 outweighs the steady but lower start of the Al₂O₃ surface. Summing those cycles gives SiO₂ = 4.5 + 2.4 + 2.7 = 9.6, while Al₂O₃ = 2.5 + 3.2 + 3.4 = 9.1.


Figure 7. CLD simulations. (A) Cumulative height growth and (B) roughness per cycle.

The  chart shows the growth per cycle for two methods, CLD (blue) and ALD (red), over ten cycles. CLD growth is less uniform than ALD under the conditions shown.

The line chart displays the surface roughness for two methods, CLD and ALD, over cycles. CLD (blue) exhibits a progressive roughening trend, ALD (red) remains roughly constant .

| Cycle | Growth per cycle, A: ALD | Growth per cycle, A: CLD |
|---|---|---|
| 1 | 1.0 | 0.2 |
| 2 | 0.9 | 0.9 |
| 3 | 0.8 | 1.5 |
| 4 | 0.9 | 0.2 |
| 5 | 1.1 | 1.0 |
| 6 | 0.8 | -0.8 |
| 7 | 1.1 | 0.5 |
| 8 | 1.1 | 4.7 |
| 9 | 0.9 | 0.4 |
| 10 | 1.1 | 1.0 |

| Cycle | Surface Roughness, A:  ALD| Surface Roughness, A: CLD|
|---|---|---|
| 0 | - | 0.7 |
| 1 | 0.8 | 1.2 |
| 2 | 1.1 | 2.2 |
| 3 | 1.2 | 3.5 |
| 4 | 1.3 | 3.8 |
| 5 | 1.5 | 5.0 |
| 6 | 1.3 | 3.7 |
| 7 | 1.2 | 4.2 |
| 8 | 1.4 | 8.5 |
| 9 | 1.4 | 7.3 |
| 10 | 1.3 | 8.5 |

Answer: The CLD process eventually switches from deposition to etching mode. The growth per cycle for CLD drops below zero at cycle 6, indicating a negative growth rate. A negative value for growth per cycle physically means the removal of material from the surface rather than addition.

Answer: ALD (GPC remains roughly constant).

Answer: ALD (surface roughness is relatively constant).

Answer: ALD (surface roughness is lower).


Figure 8. Effect of different injection stoichiometries. (A) Cumulative height growth per cycle and (B) roughness per cycle. Blue: base case. Red: half amount of water injected per cycle.

The chart shows the growth per cycle over 10 cycles for two conditions: the base case and a process using half the H₂O injected per cycle. The base case remains low and fairly steady. In contrast, halving the H₂O dose produces highly unstable growth, with large cycle-to-cycle fluctuations.

The chart illustrates the surface roughness over 10 cycles for two conditions: the base case and a process using half the H₂O injected per cycle. The base case remains relatively smooth, showing a slow increase in roughness over cycling. The half-H₂O condition exhibits significant increases in surface roughness.

| Cycle | Growth per cycle, Å (Base case) | Growth per cycle, Å (Half H₂O amount injected per cycle) |
|---|---|---|
| 1 | 0.98 | 3.07 |
| 2 | 1.22 | 5.64 |
| 3 | 1.96 | 2.57 |
| 4 | 0.98 | 18.77 |
| 5 | 1.59 | 25.15 |
| 6 | 0 | 3.31 |
| 7 | 1.22 | 47.8 |
| 8 | 5.27 | 9.44 |
| 9 | 0.85 | 3.55 |
| 10 | 1.47 | 32.0 |

| Cycle | Surface Roughness, Å (Base case) | Surface Roughness, Å (Half H₂O amount injected per cycle) |
|---|---|---|
| 0 | 1.17 | 1.17 |
| 1 | 1.76 | 4.5 |
| 2 | 2.35 | 10 |
| 3 | 4.11 | 12.35 |
| 4 | 4.51 | 29.01 |
| 5 | 5.49 | 38.23 |
| 6 | 3.72 | 43.13 |
| 7 | 4.51 | 67.84 |
| 8 | 8.63 | 64.90 |
| 9 | 7.45 | 67.25 |
| 10 | 8.43 | 72.15 |

Answer: Halving the H₂O dose makes the growth much less stable from cycle to cycle. In the base case, the growth per cycle stays low and fairly consistent, with only small fluctuations across the 10 cycles. With half H₂O, the growth becomes unstable, showing large swings.  So the reduced H₂O dose breaks the steady, repeatable growth behavior.

Answer: Yes

Answer: To obtain smooth films, the base-case  (stoichiometric) dosing  should be selected. The base case maintains a consistently low surface roughness (below 10 Å ) throughout the sequence. By contrast, the half-H₂O condition exhibits a rapid and substantial increase in roughness, reaching over 70 Å by the end of the measurement. Overall, this behavior is consistent with the development of a rough surface.

Answer: Using substoichiometric (insufficient) amounts of H₂O leads to surface roughening.


Figure 11. Coverage (\%) versus rotation speed (rad/s) for (a) Hacac step, (b) BDEAS step, and (c) ozone step.  $x_{A}$ ,  $x_{B}$ , and  $x_{C}$  represents the mole fraction of Hacac, BDEAS, and ozone, respectively.

Hacac surface coverage (%) as a function of wafer rotation speed at different reactant mole fractions, showing a general decrease with increasing rotation speed. Coverage remains nearly full at low speeds even for lower mole fractions.

BDEAS surface coverage (%) as a function of wafer rotation speed at different reactant mole fractions, showing sharper decreases at higher rotation speeds due to its noncompetitive kinetic mechanism, producing steeper and somewhat discontinuous curves.

Ozone surface coverage (%) as a function of wafer rotation speed at different reactant mole fractions, generally decreasing with increasing rotation speed, with nearly full coverage at low speeds even for lower mole fractions.

| Rotation speed (rad/s)|xHacac = 0.05|xHacac = 0.1|xHacac = 0.3|
|-----------------------|-------------|------------|------------|
|0.2|100|100|100|
|0.3|98.8|99.5|100|
|0.4|97.5|98.7|100|
|0.5|96.2|97.8|99.5|
|0.6|95.1|96.5|100|
|0.7|94.0|95.2|99.8|
|0.8|92.8|94.0|99.5|

| Rotation speed (rad/s)|xBDEAS = 0.05|xBDEAS = 0.1|xBDEAS = 0.3|
|-----------------------|-------------|------------|------------|
|0.2|100|100|100|
|0.3|97.5|98.5|100|
|0.4|95.0|97.0|99.2|
|0.5|92.0|95.0|98.0|
|0.6|89.5|93.0|97.5|
|0.7|87.0|91.5|97.0|
|0.8|85.0|90.0|96.5|

| Rotation speed (rad/s)|xO3 = 0.05|xO3 = 0.1|xO3 = 0.3|
|-----------------------|----------|---------|---------|
|0.2|100|100|100|
|0.3|98.8|99.5|100|
|0.4|97.5|98.7|100|
|0.5|96.2|97.8|99.5|
|0.6|95.1|96.5|100|
|0.7|94.0|95.2|99.8|
|0.8|92.8|94.0|99.5|

Answer: The coverage versus rotation speed data helps identify optimal operating conditions for the ASALD process. By selecting lower rotation speeds or higher reagent mole fractions, full surface coverage can be achieved for Hacac, BDEAS, and ozone steps. Understanding the steep coverage decrease for BDEAS allows engineers to adjust the mole fraction or rotation speed to avoid incomplete coverage. These insights ensure uniform thin film deposition, efficient reagent use, and controlled reaction kinetics, which are critical for producing high-quality films with predictable thickness and surface properties.

Answer: The BDEAS step shows the steepest decrease in coverage, attributed to its noncompetitive kinetic mechanism.

Answer: Yes. Higher rotation speeds decrease the exposure time of the wafer to the reagents, resulting in lower surface coverage.

Answer: Wafer rotation speed (lower speeds increase coverage), Mole fraction of the reagent (higher mole fractions increase coverage), Kinetic mechanism of the reaction (e.g., noncompetitive behavior of BDEAS), Exposure time of the wafer to the reagent

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/38/Sungil Yun et al.pdf


Figure 11. Energetics for the bound reactants (BR), transition state (TS), bound products (BP) and unbound products (UP) relative to the unbound reactants (UR) for the reaction of  $\mathrm{SiH}_2(\mathrm{NH}_2)_2$  (triangles, dashed lines),  $\mathrm{SiH}_2\mathrm{DMA}_2$  (squares, solid lines) with the cluster models  $(\mathrm{Si}_3\mathrm{N}_4)_4(\mathrm{NH}_3)_{12}$  (red) and  $(\mathrm{Si}_3\mathrm{N}_4)_4(\mathrm{H}_2\mathrm{O})_{12}$  (green). The table inset presents the  $E_{\mathrm{act}}$  values for the precursors with the  $\mathrm{NH}_2$  and OH covered surfaces.  $\Delta E$  values are given in  $\mathrm{kJ / mol}$  and were determined from BP86/SV(P) DFT calculations.

The line chart illustrates the energy changes ($\Delta E$ in kJ/mol) for two compounds, SiH2(NH2)2 and SiH2DMA2, across four stages: UR, BR, TS, BP, and UP. The chart also includes surface types (NH2 and OH) for comparison.

| Step | SiH₂(NH₂)₂ on NH₂ Surface | SiH₂DMA₂ on NH₂ Surface | SiH₂(NH₂)₂ on OH Surface | SiH₂DMA₂ on OH Surface |
|------|---------------------------|--------------------------|---------------------------|--------------------------|
| UR   | 0                         | 0                        | 0                         | 0                        |
| BR   | -10                     | -30                    | -65                     | -50                    |
| TS   | +70                     | +70                   | +10                    | 0                        |
| BP   | 20                       | 20                      | -30                    | -80                    |
| UP   | 5                         | 5                         | -90                    | -50                      |

Answer:
The activation energies for the precursors are as follows
1. SiH₂(NH₂)₂  on NH₂ Surface =    98.29   kJ/mol
2.  SiH₂(NH₂)₂ on   OH Surface  = 79.13   kJ/mol
3. SiH₂DMA₂  on NH₂ Surface =    79.97   kJ/mol
4.  SiH₂DMA₂ on   OH Surface  = 51.74   kJ/mol

Answer: The larger steric interactions experienced by SiH2DMA2 with the amine-covered surface compared with the hydroxyl-covered surface destabilize BR. The same steric interactions explain the weaker adsorption by SiH2DMA2 relative to SiH2(NH2)2 on both substrates

Answer:
The higher energy of BR reflects a reduced bond strength of the precursor to the surface. This may increase the probability of the precursor returning unreacted to the gas phase at ALD temperatures and may prevent the remaining reaction steps occurring. This initial BR step is therefore crucial in determining the deposition rate of a
precursor and was chosen as a metric for ALD reactivity of other potential precursors.

Answer: Overall, SiH₂(NH₂)₂  and SiH₂DMA₂ on NH₂ Surface have higher energy for all the states compared to OH surface

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/53/Ciaran A. Murray et al.pdf


Figure 6.  $\Delta E$  for the hydrolysis  $\mathrm{(YH = H_2O)}$  and amination  $\mathrm{(YH =}$ $\mathrm{NH_3}$  ) of various silicon precursors calculated using eqs 1a and 1b from BP86/TZVPP total energies.

The figure plots the change in energy (ΔE) in kJ/mol for various compounds when interacting with H2O and NH3.

| Precursor       | ΔE (kJ/mol) with H₂O | ΔE (kJ/mol) with NH₃ |
|------------------|------------------------|------------------------|
| SiH₂Cl₂         | 0                      | +45                   |
| SiH₂DMA₂        | -30                    | 0                     |
| SiH₂HFMA₂       | -60                    | -20                   |
| SiH₂EMA₂        | -50                    | 0                     |
| BDEAS           | -55                    | -2                    |
| BTBAS           | -60                    | -10                   |
| SiH₂CH₃         | -110                   | -70                   |
| SiH₄            | -80                    | -30                   |

Answer: ΔEhyd was significantly more negative than ΔEamin by 47.14 kJ/mol. This value |ΔE| corresponds to the reaction SiH2(NH2)2 + 2H2O ↔ SiH2(OH)2 + 2NH3).

Answer: The difference ΔE between hydration and amination means that functional group elimination from difunctionalized silane precursors is thermodynamically more favorable on OH covered SiO2 surfaces than on NH2/NH-covered Si3N4 surfaces. This appears to correlate with the much slower ALD growth rates for silicon nitride compared with silicon dioxide.

Answer:
1. SiH₂Cl₂
2. SiH₂DMA₂
3.  SiH₂HFMA₂
4. SiH₂EMA₂
5. BDEAS
6.  BTBAS
7. SiH₂CH₃
8.  SiH₄

Answer: Yes


Figure 8. Energetics for the bound reactants (BR), transition state (TS), bound products (BP) and unbound products (UP) relative to the unbound reactants (UR) for the reaction of (a)  $\mathrm{SiH}_2(\mathrm{NH}_2)_2$  and (b)  $\mathrm{SiH}_2\mathrm{DMA}_2$  precursor with the surface group models  $\mathrm{SiH}_3\mathrm{-OH}$  (red diamonds),  $\mathrm{SiH}_3\mathrm{-NH}_2$  (green squares), and  $\mathrm{SiH}_3\mathrm{-NH - SiH}_3$  (blue triangles).  $\Delta E$  values are given in  $\mathrm{kJ / mol}$  and were determined using BP86/SV(P) DFT calculations.

The line chart displays changes in ΔE (kJ/mol) for  SiH2(NH2)2 on surface of three different species (SiH3-OH, SiH3-NH2, SiH3-NH-SiH3) across five states (UR, BR, TS, BP, UP).

The line chart shows changes in ΔE (kJ/mol) for  SiH2DMA2 precursor on surface of three different species (SiH3-OH, SiH3-NH2, SiH3-NH-SiH3) across five states (UR, BR, TS, BP, UP).

| Step | SiH₃–OH | SiH₃–NH₂ | SiH₃–NH–SiH₃ |
|------|---------|----------|--------------|
| UR   | 0       | 0        | 0            |
| BR   | -40     | -20      | -15          |
| TS   | +80     | +60      | +70          |
| BP   | -60     | -30      | -25          |
| UP   | -80     | -10      | -5           |

| Step | SiH₃–OH | SiH₃–NH₂ | SiH₃–NH–SiH₃ |
|------|---------|----------|--------------|
| UR   | 0       | 0        | 0            |
| BR   | -35     | -18      | -15          |
| TS   | +75     | +55      | +65          |
| BP   | -55     | -28      | -25          |
| UP   | -75     | -12      | -8           |

Answer: Yes

Answer: The reactions leading to BR, BP and UP (optimized to local minima) on the SiH3−OH model surface were calculated to be more exothermic than those on the SiH3−NH2 and SiH3−NH−SiH3 systems, consistent with the results of the thermodynamic model

Answer: These calculations ignored temperature effects that may reduce the significance of these energy differences.

Answer:
The ΔE values for the SiH3−NH2 and SiH3−NH−SiH3 models were almost identical, indicating the similar chemistry of primary (NH2) and secondary (NH) amine
groups. The transition state energy barriers or activation energies for SiH2(NH2)2 and SiH2DMA2 are quite similar to Eact for both precursors,  with the SiH3−OH substrate lower than with SiH3−NH2/SiH3−NH−SiH3 substrates.


Figure 10. The evolution of the growth rate during the  $\mathrm{Al}_2\mathrm{O}_3$  ALD starting with two different initial  $-\mathrm{OH}$  concentrations at  $300^{\circ}\mathrm{C}$ .

Growth per cycle is plotted against ALD cycles. Higher initial OH gives higher growth from the start. Lower OH shows slow early growth and gradual increase.

| ALD cycles | Growth per cycle (Å), H: 6% | Growth per cycle (Å), H: 0.5% |
|---|---|---|
| 1 | ~0.50 | ~0.10 |
| 2 | ~0.50 | ~0.10 |
| 3 | ~0.55 | ~0.15 |
| 4 | ~0.40 | ~0.15 |
| 5 | ~0.50 | ~0.20 |
| 6 | ~0.60 | ~0.20 |
| 7 | ~0.70 | ~0.30 |
| 8 | ~0.46 | ~0.40 |
| 9 | ~0.50 | ~0.30 |
| 10 | ~0.46 | ~0.45 |
| 11 | ~0.56 | ~0.30 |
| 12 | ~0.46 | ~0.40 |

Answer: Fewer OH groups limit precursor adsorption in early cycles. Reactive sites must form gradually through repeated ALD reactions. Thus, low initial OH lead to suppressed early-cycle growth.

Answer: The 6% OH condition.

Answer: It implies a higher density of reactive OH sites. More sites allow more precursor reactions per cycle, increasing growth efficiency.

Answer: The figure indicates that increasing or stabilizing initial OH coverage can reduce incubation effects and improve early-cycle growth uniformity. Process steps such as surface pre-treatment or controlled exposure conditions could be used to achieve this. Understanding the cycle-dependent fluctuations also helps in selecting suitable cycle counts to obtain consistent film thickness.

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/55/Zheng Hu et al.pdf


Figure 11. The evolution of the surface roughness during the  $\mathrm{Al}_2\mathrm{O}_3$  ALD starting with two different initial  $-\mathrm{OH}$  concentrations at  $300^{\circ}\mathrm{C}$ .

The figure shows surface roughness during Al₂O₃ ALD at 300 °C. High initial OH gives an early roughness peak and later smoothing. Low initial OH shows steady roughness increase with cycle number.

| ALD cycles | Roughness (Å), H: 6% | Roughness (Å), H: 0.5% |
|---|---|---|
| 1 | ~1.40 | ~0.95 |
| 3 | ~1.55 | ~1.00 |
| 5 | ~1.80 | ~1.30 |
| 6 | ~2.00 | ~1.40 |
| 8 | ~1.90 | ~1.85 |
| 9 | ~1.88 | ~1.85 |
| 11 | ~1.70 | ~1.95 |
| 12 | ~1.65 | ~2.05 |

Answer: When starting from a high OH concentration, surface roughness increases rapidly during early ALD cycles due to active growth and then decreases as the surface becomes more uniformly covered. In contrast, a low OH concentration leads to a slower but more continuous buildup of roughness as reactive sites gradually form. This indicates that initial surface chemistry strongly influences how roughness develops over time.

Answer: The high-OH case shows a non-monotonic trend with a clear maximum in roughness at intermediate cycles followed by a decline. By comparison, the low-OH case shows a largely monotonic increase in roughness that continues into later cycles. These contrasting trends suggest different dominant growth and relaxation mechanisms depending on initial OH coverage.

Answer: The relationship implies that higher OH coverage initially promotes more uniform nucleation and surface reactions, eventually smoothing the surface as growth proceeds. Lower OH coverage delays uniform nucleation, leading to rougher and more heterogeneous surface structures over time. Thus, surface hydroxylation is closely tied to morphological evolution during ALD.

Answer: The trends suggest that higher initial OH concentrations can help limit long-term surface roughness by promoting more uniform growth after early cycles. Process strategies such as surface pre-treatment or controlled OH generation could therefore improve film smoothness. Monitoring roughness evolution also helps determine optimal cycle numbers to avoid roughness buildup at later stages.


Figure 12. The evolution of the surface  $-\mathrm{OH}$  concentration during the ALD process at two different temperatures.

The figure shows how surface −OH concentration increases during ALD. The increase is faster at 300 °C than at 150 °C. Higher temperature leads to much higher −OH coverage.

| ALD cycles | –OH concentration (nm⁻²), 150 °C | –OH concentration (nm⁻²), 300 °C |
|---|---|---|
| 0 | 0.10 | ~0.10 |
| 1 | 0.18 | ~0.20 |
| 2 | 0.20 | ~0.25 |
| 3 | 0.30 | ~0.40 |
| 4 | 0.48 | ~0.60 |
| 5 | 0.60 | ~0.90 |
| 6 | 0.70 | ~1.10 |
| 7 | 0.95 | ~1.50 |
| 8 | 1.20 | ~1.80 |

Answer: No

Answer: Cycle 1.

Answer: The strong temperature dependence indicates that surface hydroxylation is facilitated by thermally activated mechanisms such as ligand removal and reactive site formation. At 300 °C, these processes proceed more efficiently, creating a higher density of reactive –OH groups that can participate in subsequent ALD reactions. Thus, the evolving surface structure at elevated temperature enhances the reactivity and continuity of the ALD growth process.

Answer: Approximately 0.6 nm⁻².


Figure 13. The evolution of the surface roughness during the ALD process at two different temperatures.

The figure shows growth per cycle during ALD at 150 °C and 300 °C. Growth decreases during the first few cycles at both temperatures. After this, growth increases with cycle number. The increase is stronger at 300 °C than at 150 °C.

| ALD cycles | Growth per cycle (Å), 150 °C | Growth per cycle (Å), 300 °C |
|---|---|---|
| 1 | ~0.11 | ~0.08 |
| 2 | ~0.04 | ~0.07 |
| 3 | ~0.03 | ~0.15 |
| 4 | ~0.10 | ~0.13 |
| 5 | ~0.10 | ~0.18 |
| 6 | ~0.14 | ~0.17 |
| 7 | ~0.23 | ~0.30 |
| 8 | ~0.21 | ~0.38 |

Answer: The incubation (or nucleation) stage.

Answer: Around cycle 7.

Answer:
-Slower formation of reactive surface sites
-Reduced reaction kinetics at lower temperature

Answer: The figure suggests that higher temperatures can be used to achieve faster growth once incubation effects are overcome, which may be beneficial for throughput-sensitive applications. Conversely, lower temperatures may be chosen when finer control over early growth is required. Understanding the trade-off between incubation behavior and steady-state growth helps optimize temperature selection for specific film quality and performance goals.


Figure 3. Total density profiles after zero (blue), four (red) and eight (green) ALD cycles as a function of the distance along the  $Z$  direction of the  $\mathrm{Al}_2\mathrm{O}_3$  film at  $300^{\circ}\mathrm{C}$ .

The figure presents total density profiles along the Z direction of an Al₂O₃ film after 0, 4, and 8 ALD cycles. All three profiles show a high initial density near the substrate interface, followed by a rapid decrease and a secondary peak around 5–7 Å. With increasing ALD cycles, the density extends further into the film, producing broader and more gradual decay profiles. The L8 curve maintains higher density values at larger Z distances, indicating thicker and more fully developed film growth compared with L0 and L4.

| Z (Å) | Density L0 (g/cm³) | Density L4 (g/cm³) | Density L8 (g/cm³) |
|---|---|---|---|
| 3  | 1.15 | 1.15 | 1.15 |
| 4  | 0.58 | 0.58 | 0.58 |
| 5  | 0.65 | 0.63 | 0.61 |
| 6  | 0.80 | 0.87 | 0.85 |
| 7  | 0.56 | 0.70 | 0.70 |
| 8  | 0.25 | 0.58 | 0.68 |
| 9  | 0.10 | 0.38 | 0.58 |
| 10 | 0.03 | 0.20 | 0.50 |
| 11 | 0.00 | 0.10 | 0.40 |
| 12 | 0.00 | 0.05 | 0.30 |
| 13 | 0.00 | 0.00 | 0.18 |
| 14 | 0.00 | 0.00 | 0.10 |
| 15 | 0.00 | 0.00 | 0.00 |
| 17 | 0.00 | 0.00 | 0.00 |

Answer: Increasing the number of ALD cycles systematically shifts the density profiles outward along the Z direction and broadens their shapes. L0 shows the steepest decay, indicating a thinner initial film, whereas L4 and especially L8 retain significant density at larger Z values. The secondary peak present in all curves becomes more pronounced and moves slightly outward as the film grows. Overall, the progression from L0 to L8 reflects the accumulation of material and the development of a thicker, more homogeneous oxide layer.

Answer: A locally dense atomic layer or sublayer within the growing Al₂O₃ film.

Answer: A broader density distribution suggests a more extended and uniformly packed film, which may enhance barrier properties such as moisture resistance, dielectric strength, and mechanical stability. Greater density retention at larger Z distances indicates fewer voids or low-density regions, contributing to improved film continuity. These characteristics generally lead to better long-term performance in applications where conformal coverage and structural integrity are critical.

Answer:
- The steepness of the initial density decay, indicating early nucleation efficiency.
- The height and location of the secondary peak, reflecting sublayer formation.
- The extent of density at larger Z values, showing how far the film has grown.
- Differences between L0, L4, and L8 that reveal transition from initial nucleation to steady-state growth.


Figure 4. Number density profiles for O, Al and H as a function of the distance along the  $Z$  direction of the  $\mathrm{Al}_2\mathrm{O}_3$  film at  $300^{\circ}\mathrm{C}$ .

The figure shows number-density profiles of O, Al, and H atoms across the Z direction of an Al2O3 film at 300 °C. Oxygen exhibits the highest and most structured density distribution near the film surface, with prominent peaks indicating layered arrangements. Aluminum shows a similar but slightly shifted density profile with a lower overall magnitude. Hydrogen appears in much smaller concentrations and peaks closer to the mid-film region before tapering off. Together these profiles describe the atomic layering and composition variation within the film thickness.

| Z (Å) | O density (nm⁻³) | Al density (nm⁻³) | H density (nm⁻³) |
|----|----|----|----|
| 3  | 14.0 | 17.0 | 0.5 |
| 4  | 15.0 | 4.0  | 0.5 |
| 5  | 10.0 | 8.0  | 1.5 |
| 6  | 15.5| 10.0 | 1.5 |
| 7  | 13.0 | 8.0  | 2.0 |
| 8  | 10.0 | 6.0  | 3.0 |
| 9  | 8.0  | 4.0  | 4.0 |
| 10 | 4.0  | 2.0  | 4.0 |
| 11 | 3.0  | 1.0  | 3.0 |
| 12 | 2.0  | 0.0  | 2.0 |
| 13 | 0.5| 0.0  | 1.0 |
| 14 | 0.0  | 0.0  | 0.0 |
| 15 | 0.0  | 0.0  | 0.0 |
| 16 | 0.0  | 0.0  | 0.0 |

Answer: Approximately 6 Å.

Answer: Yes, after approximately Z = 11 Å, the H density remains positive while O drops toward zero.

Answer: None; all densities have reached 0 nm⁻³ by this distance.

Answer:
- The relative heights and positions of the O and Al peaks, indicating layered ordering.
- The full width and decay behavior of the density tails as Z increases.
- The presence and magnitude of hydrogen density, as it reflects realistic surface hydroxylation or defect levels.
- The overall stoichiometric consistency inferred from integrated densities.


Figure 5.Ratio of Al[4]/Al[3] after zero (blue), four (red) and eight (green) ALD cycles as a function of the distance along the  $Z$  direction of the  $\mathrm{Al}_2\mathrm{O}_3$  film at  $300^{\circ}\mathrm{C}$

The figure shows the ratio of four-fold to three-fold coordinated aluminum (Al[4]/Al[3]) as a function of depth (Z direction) in an Al2O3 film after 0, 4, and 8 ALD cycles at 300 °C. The ratio is lowest and rapidly decays with depth for L0, indicating limited tetrahedral coordination. With increasing ALD cycles (L4 and L8), the Al[4]/Al[3] ratio increases significantly near the surface and exhibits pronounced oscillations, followed by a sharp decrease toward the film interior. This suggests cycle-dependent structural evolution of aluminum coordination across the film thickness.

| Z (Å) | Al[4]/Al[3] (L0) | Al[4]/Al[3] (L4) | Al[4]/Al[3] (L8) |
|---|---|---|---|
| 5 | 5.0 | 5.0 | 10 |
| 6 | 3.0 | 6.2 | 13 |
| 7 | 2.5 | 7.5 | 16 |
| 8 | 2.0 | 10.0 | 14.5 |
| 9 | 1.5 | 8.5 | 21 |
| 10 | 0.0 | 7.5 | 16 |
| 11 | 0.0 | 7.5 | 11.5 |
| 12 | - | 10.0 | 18.5 |
| 13 | — | 0.0 | 6.0 |
| 14–16 | — | — | 3 → ~0 |

Answer: Yes

Answer: Eight ALD cycles (L8).

Answer:
- Increased tetrahedral aluminum coordination
- Higher network connectivity
- Surface regions closer to bulk-like Al2O3 structure

Answer: Depth-dependent coordination provides insight into how film structure develops during ALD and how surface reactions propagate inward. Variations in Al coordination affect film density, chemical stability, and dielectric behavior. Understanding these trends helps optimize ALD cycle numbers and processing conditions for applications requiring controlled structural and functional properties.


Figure 6.Ratio of O[3]/O[2] after zero (blue), four (red) and eight (green) ALD cycles as a function of the distance along the  $Z$  direction of the  $\mathrm{Al}_2\mathrm{O}_3$  film at  $300^{\circ}\mathrm{C}$

The figure shows the ratio of three-fold to two-fold coordinated oxygen (O[3]/O[2]) as a function of depth in an Al2O3 film after 0, 4, and 8 ALD cycles at 300 °C. For all cases, the ratio is highest near the surface and decreases rapidly toward the film interior. Increasing ALD cycles shift the O[3]/O[2] distribution to higher values and extend the depth range over which three-fold coordination persists, indicating progressive structural densification near the surface.

| Z (Å) | O[3]/O[2] (L0) | O[3]/O[2] (L4) | O[3]/O[2] (L8) |
|---|---|---|---|
| 5 | 1.0 | 1.20 | 1.00 |
| 6 | 1.1 | 1.55 | 1.90 |
| 7 | 1.0 | 1.70 | 2.10 |
| 8 | 0.7 | 1.20 | 1.65 |
| 9 | 0.35 | 0.75 | 1.60 |
| 10 | 0.2 | 0.80 | 1.30 |
| 11 | 0.0 | 0.30 | 1.00 |
| 12 | 0.0 | 0.20 | 0.80 |
| 13 | 0.0 | 0.00 | 0.50 |
| 14–16 | — | 0.00 | 0.1 → 0 |

Answer: Yes

Answer: Eight ALD cycles (L8).

Answer:
- Higher prevalence of three-fold coordinated oxygen
- Increased network connectivity
- More bulk-like oxide bonding configuration

Answer: Oxygen coordination directly influences film density, mechanical stability, and dielectric properties of Al2O3. Variations in O[3]/O[2] with depth reveal how surface reactions evolve during ALD and how structural relaxation progresses into the film. Such insight is essential for designing ALD processes that produce uniform, high-quality oxide layers for electronic and protective applications.


Figure 9. The evolution of the surface  $-\mathrm{OH}$  concentration during the  $\mathrm{Al}_2\mathrm{O}_3$  ALD starting with two different initial  $-\mathrm{OH}$  concentrations at  $300^{\circ}\mathrm{C}$ .

The figure shows the evolution of surface –OH concentration during Al2O3 ALD at 300 °C for two different initial –OH surface coverages. For the high initial –OH case (6.0%), the surface concentration increases rapidly during early cycles and then approaches a plateau near 5 nm⁻². In contrast, the low initial –OH case (0.5%) exhibits a slower but continuous increase throughout the ALD cycles, eventually reaching much lower values than the high-OH surface. This highlights the strong influence of initial surface chemistry on hydroxyl regeneration behavior.

| ALD cycles | –OH concentration (nm⁻²), H: 6.0% | –OH concentration (nm⁻²), H: 0.5% |
|---|---|---|
| 1 | 2.8 | 0.2 |
| 3 | 3.8 | 0.4 |
| 5 | 4.0 | 0.9 |
| 7 | 4.6 | 1.4 |
| 8 | 4.9 | 1.8 |
| 9 | 4.9 | 2.0 |
| 10 | 4.9 | 2.6 |
| 12 | 5.1 | 3.0 |

Answer: No

Answer: The surface starting with 6.0% initial –OH concentration.

Answer:
- Rapid increase during early ALD cycles
- Reduced slope at intermediate cycles
- Nearly constant –OH concentration at later cycles

Answer: Surface –OH groups act as key reactive sites for precursor adsorption during ALD. Knowing how their concentration evolves helps in predicting growth rates, incubation behavior, and surface reactivity over multiple cycles. This information is critical for selecting surface pre-treatments and process conditions that lead to uniform and controlled film growth.


Figure 15. Fraction of lattice site vacant at the end of the simulation after  $2 \mathrm{~s}$  of deposition (10 cycles). It is evident that the film growth is slow at low temperature (blue) because the lattice sites are occupied only up to a  $9 \mathrm{\AA}$  thickness. At slightly higher temperatures, the film grows faster but the deposited film contains many defects and has a lower density of atoms than a bulk  $\mathrm{ZnO}$ . The fraction of defects decreases with increasing temperature.

The line chart illustrates the fraction of vacant lattice sites along the z-axis at various temperatures. Where the different temperatures result in different profiles also related to GPC.

| z-axis / angstrom | 27 °C | 52 °C | 77 °C | 127 °C | 177 °C |
|---|---|---|---|---|---|
| 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| 5.00 | 0.60 | 0.30 | 0.28 | 0.25 | 0.20 |
| 10.00 | 0.75 | 0.28 | 0.25 | 0.15 | 0.15 |
| 15.00 | 0.95 | 0.40 | 0.25 | 0.15 | 0.15 |
| 20.00 | 1.00 | 0.70 | 0.25 | 0.15 | 0.15 |
| 25.00 | 1.00 | 0.95 | 0.50 | 0.15 | 0.15 |
| 30.00 | 1.00 | 1.00 | 0.95 | 0.75 | 0.75 |
| 35.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 40.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |

Answer: It seems that if the line reaches the value 1 this represents that the growth has stopped, indicating that for higher temperature the film thickness increases.

Answer: At the interface between the starting surface and at the surface.

Answer: About 10 angstrom for the process' at 127 and 177 degrees. The rest of the material shows little vacancies and can be seen as the bulk.

Answer: Vacancies in the lattice structure can act as charge traps, resulting in lower performances.

icdar2026-competition-data/train/atomic-layer-deposition/simulation-usecase/8/Timo Weckman et al.pdf


Figure 16. Fraction of lattice sites in the film that contain an ethyl-ligand. The fraction of sites containing an ethyl-ligand peaks at the beginning of the deposition. The peak then levels down to about 20 to  $25\%$  of sites containing an ethyl-ligand.

The line chart illustrates the fraction of sites containing a ligand along the z-axis at various temperatures (27°C, 77°C, 127°C, and 177°C). The highest fraction occurs around 5 angstroms for all temperatures, with a subsequent decline.

| z-axis / angstrom | 27 °C | 77 °C | 127 °C | 177 °C |
|---|---|---|---|---|
| 0 | 0.00 | 0.00 | 0.00 | 0.00 |
| 3 | 0.48 | 0.48 | 0.35 | 0.30 |
| 5 | 0.20 | 0.20 | 0.20 | 0.20 |
| 10 | 0.15 | 0.24 | 0.24 | 0.24 |
| 15 | 0.00 | 0.24 | 0.24 | 0.24 |
| 20 | 0.00 | 0.24 | 0.24 | 0.24 |
| 25 | 0.00 | 0.10 | 0.15 | 0.15 |
| 30 | 0.00 | 0.00 | 0.00 | 0.00 |
| 35 | 0.00 | 0.00 | 0.00 | 0.00 |
| 40 | 0.00 | 0.00 | 0.00 | 0.00 |

Answer: Deep in the film, right at the interface between the substrate and the film. This is irrespective of the deposition temperature.

Answer: ABout 24 degrees.

Answer: The GPC is roughly equal as for both temperatures the film extends equally far in the z-direction.

Answer: 1:0.50:0.50


Figure 6. Change in energy as a function of water molecules as well as the averaged adsorption energy per adsorbed water molecule. At the ethyl-coverage of 7.1 ethyl  $\mathrm{nm}^{-2}$ , the adsorption bond of a single water molecule is strong. However, inclusion of more water molecules weakens the average adsorption bond because of steric hindrance. After three water molecules, no further water can adsorb to the surface.

The line chart illustrates the trend of overall adsorption energy and averaged adsorption energy per H₂O molecule as the number of H₂O molecules increases, where the adsorption energy minimizes after the adsorption of three water molecules.

| Number of H₂O molecules in the system | Overall adsorption energy | Averaged adsorption energy per H₂O |
|---|---|---|
| 1 | -1.25 | -1.25 |
| 2 | -1.75 | -0.80 |
| 3 | -2.25 | -0.75 |
| 4 | -2.1 | -0.5 |
| 5 | -2.25 | -0.5 |

Answer: This can be concluded by the fact that the overall adsorption energy does not further decrease with increasing number of adsorbed water molecules.

Answer: Linear

Answer: Water reacts with the remaining ligands at the surface. If these are all removed the water can no longer adsorb.

Answer: -2.25 eV.


Figure 9. Simulated QCM data from the kMC model. Initially, the growth rate is the same for all temperatures when the surface becomes saturated with DEZ. However, after ethyl-saturation, the different temperature graphs diverge as the elimination of ethyl-ligands is low at low temperatures.

The chart shows the mass gain over time at different temperatures (27°C, 77°C, 127°C, 177°C). The mass gain increases stepwise with time, indicating a cumulative effect, characteristic of ALD.

| Time / seconds | Mass-gain / ng cm⁻² 27 | Mass-gain / ng cm⁻² 77 | Mass-gain / ng cm⁻² 127 | Mass-gain / ng cm⁻² 177 |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 |
| 1 | 120 | 120 | 120 | 120 |
| 2 | 225|250|300|300|
| 4 | 300 |350|450|450|
| 6 | 300 |450|600|600|
| 8 | 300 |740|900|900|
| 10 | 375 |850|1050|1050|
| 12 | 375 |975|1200|1200|
| 14 | 375 |1100|1350|1350|
| 16 | 375 |1250|1500|1500|

Answer: The duration of single cycle is 1.6 seconds. This can be concluded from the graph that there are 10 cycles in a time span of 16 seconds in the figure.

Answer: No there is no cyclic growth. For ALD the increase every cycle should be the same, this is not the case fpr 27 degrees Celcius.

Answer: 127, 177 degrees Celcius.

Answer: Water can condensate below a 100 degrees Celcius, so a process temperature of 77 degrees can result in liquid water in the reactor.


Figure 4.  $\mathrm{ZnO}$  thickness as a function of the number of ALE cycles for temperatures between  $100$  and  $250^{\circ}\mathrm{C}$ , as measured by in situ SE.

The plot shows change in ZnO thickness as a function of number of ALE cycles at various temperatures

| Number of ALE Cycles | 100 °C (Å) | 150 °C (Å) | 200 °C (Å) | 250 °C (Å) |
|----------------------|-----------|-----------|-----------|-----------|
| 0                   | 585       | 585       | 585       | 585       |
| 10                  | 580       | 575       | 570       | 565       |
| 20                  | 575       | 565       | 555       | 545       |
| 30                  | 570       | 555       | 540       | 530       |
| 40                  | 565       | 545       | 530       | 525       |
| 50                  | 560       | 540       | 525       | 520       |

Answer: No, in-situ SE

Answer:
The EPCs at different temperatures are as follows,
1.  100 °C, 0.54 ± 0.05 Å
2.  150 °C, 0.97 ± 0.07  Å
3.   200 °C, 1.25 ± 0.08  Å
4.   250 °C, 1.31 ± 0.08 Å

Answer: The ZnO thickness can be seen to decrease linearly with the number of ALE cycles for each  temperature, in line with a layer-by-layer etching mechanism.

Answer: As seen in image, the thicknesses decrease more at higher temperatures, thus etch per cycle and the ALE increases with increase in temperature

icdar2026-competition-data/train/atomic-layer-etching/experimental-usecase/11/Isotropic Atomic Layer Etching of ZnO Using Acetylacetone and O2 Plasma.pdf


Figure 3. Etch rate per cycle of the atomic layer etching (ALE) for (a) varying  $\mathrm{O_2}$  and fixed  $\mathrm{BCl_3}$  plasma times per cycle and (b) varying  $\mathrm{BCl_3}$  and fixed  $\mathrm{O_2}$  plasma times.

The etch rate increases linearly with increasing O₂ time/cycle for both BCl₃ time/cycles of 60 sec and 30 sec.

The etch rate increases linearly with increasing BCl₃ time/cycle for both O₂ time/cycles of 60 sec and 30 sec.

| O₂ time/cycle (sec) | Etch rate [nm/cycle] BCl₃ time/cycle 30 sec | Etch rate [nm/cycle] BCl₃ time/cycle 60 sec |
|---|---|---|
| 0 | 0.0 | 0.0 |
| 30 | 0.4 | 0.4 |
| 45 | 0.5 | 0.6 |
| 50 | 0.5 | 0.6 |
| 60 | 0.55 | 0.7 |
| 90 | 0.55 | 0.7 |

| BCl₃ time/cycle (sec) | Etch rate [nm/cycle] O₂ time/cycle 30 sec | Etch rate [nm/cycle] O₂ time/cycle 60 sec |
|---|---|---|
| 0 | 0.0 | 0.0 |
| 30 | 0.4 | 0.6 |
| 45 | 0.4 | 0.7 |
| 50 | 0.4 | 0.7 |
| 90 | 0.4 | 0.7 |

Answer: Figure 3 shows that the etch rate per ALE cycle increases with increasing O₂ plasma exposure up to 60 s when the BCl₃ plasma time is held constant, indicating that longer oxidation enhances the formation of a removable surface layer. Beyond 60 s, the etch rate plateaus, suggesting that the surface becomes fully oxidized and that further O₂ exposure does not increase the amount of material available for removal, consistent with self-limiting behaviour. Similarly, when the O₂ plasma time is fixed at 60 s and the BCl₃ exposure is increased, the etch rate rises until 45 s, after which it also saturates, implying that the chlorination and removal step has become complete.

Answer: 0.4 nm/cycle.

Answer: 0.7 nm/cycle.

Answer: 0.6 nm/cycle.

icdar2026-competition-data/train/atomic-layer-etching/experimental-usecase/13/Low-Damage and Self-Limiting (Al)GaN Etching Process.pdf


Figure 4. Etch rate when using  $\mathrm{BCl}_3$  plasma under a fixed ICP power of  $400 \mathrm{W}$  and varying bias powers.

The chart shows the etch rate of GaN and AlGaN as a function of bias power. The etch rate increases linearly with bias power for both materials.

| Bias power [W] | Etch rate [nm/min] GaN | Etch rate [nm/min] GaN |
|---|---|---|
| 0 | 0.0 | 0.0 |
| 5 | 1.0 | 1.0 |
| 10 | 4.0 | 2.5 |

Answer: 10 mTorr.

Answer: 400 W.

Answer: BCl3 plasma.

Answer: As the bias power increases, initially no etching is observed. Only at a bias power higher than 2 W is any etching observed. This means that above 2 W, the BCl3 plasma is energetic enough to etch the substrates without the need of O2 plasma, which also means that above 2 W, the reactions during the BCl3 plasma exposure are not self-limiting.


Figure 8.  $I - V$  curves of the fabricated Schottky diodes. (a) Forward  $I - V$  characteristics (linear scale), (b) forward  $I - V$  characteristics (log scale), (c) reverse  $I - V$  characteristics (log scale), and (d) ideality factors.

The line chart shows the relationship between forward voltage and current for two methods: ALE and Digital etching.

The line chart displays the logarithmic scale of current against forward voltage for ALE and Digital etching.

The line chart illustrates the absolute value of current against reverse voltage for ALE and Digital etching.

The line chart depicts the ideality factor n against forward voltage for ALE and Digital etching.

| Forward voltage (V) | Current [mA] ALE | Current [mA] Digital etching |
|---|---|---|
| 0.0 | 0 | 0 |
| 0.5 | 0 | 0 |
| 1.0 | 20 | 20 |
| 1.5 | 60 | 60 |
| 2.0 | 100 | 100 |

| Forward voltage (V) | Current [A] ALE | Current [A] Digital etching |
|---|---|---|
| 0.0 | 10^-11 | 10^-11 |
| 0.5 | 10^-5 | 10^-6 |
| 1.0 | 10^-2 | 10^-2 |
| 1.5 | 10^-2 | 10^-2 |
| 2.0 | 10^-1 | 10^-1 |

| Reverse voltage (V) | Current [A] ALE | Current [A] Digital etching |
|---|---|---|
| -10 | 10^-4 | 10^-4 |
| -9 | 10^-5 | 10^-5 |
| -8 | 10^-5 | 10^-5 |
| -7 | 10^-6 | 10^-6 |
| -6 | 10^-6 | 10^-6 |
| -5 | 10^-6 | 10^-6 |
| -4 | 10^-7 | 10^-7 |
| -3 | 10^-7 | 10^-7 |
| -2 | 10^-8 | 10^-8 |
| -1 | 10^-10 | 10^-8 |
| 0 | 10^-12 | 10^-10 |

| Forward voltage (V) | Ideality factor n Digital etching | Ideality factor n ALE |
|---|---|---|
| 0.0 | 0.5 | 1.4 |
| 0.05 | 1.3 | 1.3 |
| 0.1 | 1.8 | 1.2 |
| 0.15 | 1.9 | 1.2 |
| 0.2 | 2.2 | 1.1 |
| 0.25 | 2.4 | 1.2 |
| 0.3 | 2.5 | 1.1 |
| 0.35 | 1.7 | 1.2 |
| 0.4 | 1.5 | 1.2 |
| 0.45 | 1.2 | 1.2 |
| 0.5 | 1.2 | 1.5 |
| 0.55 | 1.2 | 1.7 |
| 0.6 | 1.6 | 2.3 |
| 0.65 | 2.2 |  |

Answer: About 20 mA.

Answer: It is about 10^-8 A for the ALE sample and 10^-7 A for the Digital etching sample.

Answer: Figure 8d shows that the diode fabricated using ALE exhibits a much more uniform and lower ideality factor in the low forward-bias region compared to the diode processed by digital etching, indicating reduced trap-assisted recombination and fewer defect states at the junction. In contrast, the non-uniform slope observed for the digital etching case suggests greater plasma-induced damage.

Answer: Roughly 10^-10 A for the ALE sample and 10^-9 A for the Digital etching sample.


Fig. 2. a) Film deposition rate on different materials and b) radicals concentration over  $\nu_{\mathrm{CF4}}$  in the plasma mixture, while Ar fraction is  $83.3\%$ . Negative values correspond to etching.

The figure shows the deposition rate on different materials (Si, Al2O3, HfO2, AlNx, TiN, SiO2) against the fraction of CF4 in the plasma mixture. For all materials, the deposition rate increases rapidly at low CF₄ content and then decreases again at higher CF₄ concentrations.

The figure illustrates the concentration of F, CF2, and CF species against the fraction of CF4 in the plasma mixture. For all three species, the concentration increases with CF₄ content, but the increase becomes more gradual at higher CF₄ concentrations.

| ν_CF4 (%) | Si (nm/min) | Al2O3 (nm/min) | HfO2 (nm/min) | AlNx (nm/min) | TiN (nm/min) | SiO2 (nm/min) |
|-----------|-------------|----------------|---------------|---------------|--------------|---------------|
| ~3        | ~1.5        | ~2.5           | ~2.3          | ~2.6          | ~2.2         | ~0.8          |
| ~5        | ~4.0        | ~6.0           | ~5.5          | ~6.2          | ~1.5         | ~1.2          |
| ~10       | ~3.0        | ~4.5           | ~3.5          | ~4.8          | ~−1.0        | ~−5.5         |
| ~13       | ~2.0        | ~3.8           | ~3.2          | ~4.0          | ~−0.3        | ~−5.0         |

| ν_CF4 (%) | F (cm⁻³)        | CF2 (cm⁻³)      | CF (cm⁻³)       |
|-----------|------------------|------------------|------------------|
| ~3        | ~1×10¹³          | ~5×10¹⁰         | ~2×10¹⁰         |
| ~5        | ~2×10¹³          | ~8×10¹⁰         | ~3×10¹⁰         |
| ~7        | ~5×10¹³          | ~1×10¹¹         | ~5×10¹⁰         |
| ~10       | ~8×10¹³          | ~1.6×10¹¹       | ~9×10¹⁰         |
| ~13       | ~1×10¹⁴          | ~1.8×10¹¹       | ~1.1×10¹¹       |

Answer: Both increase in value as the concentration of CH4 increases. However, F reaches a maximum value close to 10^14, while CF reaches 10^11

Answer: The CF₄ fraction (ν_CF₄) in the plasma mixture.

Answer: Yes

Answer: The plot indicates that as the CF4 fraction in the plasma increases, the F concentration rises extremely rapidly for mixtures above about 5% CF4, growing by several orders of magnitude relative to CF and CF2 (due to the logarithmic scale). While CF and CF2 radicals contribute mainly to film growth, F atoms favor the formation of volatile fluorides and thus promote etching. When F becomes predominant in the plasma, deposition is progressively suppressed and, for some materials, the overall process switches from film growth to etching.

Answer: The Fluorine radical concentration increases from 10^13 to the order of 10^14  with change in CF4 concentration and is higher than the CFx concentrations.

Answer: With increase of CF4 fraction, the deposition rate increases slowly at first and then reaches a maximum. Further increase of CF4 leads to decrease of deposition rate for Si, Al2O3, HfO2, and AlNx.  In the case of SiO2 and TiN, increase of CF4 causes a change from deposition to etching.

Answer:
No.
Fluorine-containing radicals concentration increase with the growth of CF₄ fraction in plasma mixture.

Answer: F (fluorine), with concentration near 10¹⁴ cm⁻³.

Answer: Yes

Answer: As ν_CF₄ increases, higher F and CFₓ radical densities initially enhance surface reactions, leading to higher deposition rates. Beyond the mid-fraction range, excessive fluorination and increased etching probability reduce net growth, producing the observed decline in deposition rates despite rising radical concentrations.

Answer: The radical concentration of CF has the highest dependence on the CF4 concentration.

Answer: As the CF₄ fraction increases, the concentration of fluorine-containing radicals such as F, CF, and CF₂ rises significantly, enhancing chemical reactivity at the surface. At moderate CF₄ levels, polymer-forming species promote deposition, while at higher CF₄ fractions, the high density of reactive fluorine radicals enhances bond breaking and material removal. This shift in plasma chemistry alters surface reaction pathways, causing certain materials, such as SiO₂ and TiN, to transition from net deposition to net etching.

Answer: TiN, SiO₂

Answer: Although the process involves depositing materials onto a film, come materials, such as TiN and SiO2, etch. Therefore, the deposition rate decreases as the CF4 concentration increases.

Answer: The deposition rate is lowest for SiO1 and highest for ALNx

Answer: The deposition ratio increases up to around 5% and 6% of CF4, then decreases as the concentration increases. In contrast, the concentration of CF4 and radicals is proportional, and the relationship is stronger in the case of F.

Answer: Yes

Answer: Atomic F has the fastest growth relative to CF and CF2, this implies a kinetic shift towards etching as v_CF4 increases.

Answer: Si, Al2O3, HfO2, AINx, TiN, SiO2

Answer: All materials start in net deposition at low ν_CF₄. As ν_CF₄ increases, the rates climb to a peak at low–mid ν_CF₄ and then drop. For SiO₂ and TiN, the curve crosses zero at higher ν_CF₄, this means they switch from deposition to etching. This is consistent with panel (b): the F radical grows fastest relative to CF/CF₂, pushing the surface balance toward etching.

Answer: Yes

Answer: The graph shows how the deposition rate changes with CF4 fraction for different materials. Based only on this data, AlNx looks like the best choice for industrial use. It has the highest deposition rate and stays relatively high across the whole CF4 concentration range, which would enable faster processing.

Answer: 6.6% (fastest deposition).

Answer: Below 5% CF4, as the concentration of CF4 increases, so too does the deposition rate on all substrates. Above 5%, the deposition rate generally decreases. On SiO2 however, etching occurs instead above 5% CF4 and this also occurs for TiN above 10% CF4.

Answer: TiN and SiO2.

Answer: No

Answer: The chamber pressure was kept at 10 mTorr; The plasma was always composed of 83.3% Ar the molecular fraction of CF4 varied between 3.3 and 13.3%, with the remaining fraction consisting of H2.

Answer: No

Answer: At about 7% CF4 concentration, the deposition rates of Al2O3, HfO2, Si and AlN are highest.

Answer: As the CF₄ fraction rises further, the concentration of highly reactive fluorine (F) radicals increases much more rapidly. This significant rise in 'F' radicals shifts the surface kinetics from a deposition-dominated process to an etching-dominated one, where 'F' atoms aggressively etch the deposited film.

Answer:
For higher CF₄ fractions:-

1) On SiO₂ the deposition rate becomes negative, indicating an etching process.

2) On Si, Al₂O₃, HfO₂, and AlNₓ, the deposition rate decreases but remains positive, indicating net deposition.

Answer: Yes, but only for specific materials.

Answer: SiO₂ and TiN

Answer: Low CF₄ fraction (<5%) because: (1) provides polymer deposition on target materials (Al₂O₃, AlNx, HfO₂), (2) avoids etching of potential mask materials (SiO₂, TiN)

Answer: Yes (approximately—most materials peak around 5-6.6% CF₄).

Answer: Highest: [ALNx] (~[6.1]); net etch: SiO2 (negative).

Answer: No

Answer: The materials are TiN and SiO2

Answer: The material that should be used as substrate is AlNx

Answer: An experiment can be designed such that initial thickness and final thickness can be determined after exposure to the plasma. Some materials thicknesses will decrease, others will increase.

icdar2026-competition-data/train/atomic-layer-etching/experimental-usecase/16/Selective atomic layer etching of Al2O3, AlNx and HfO2.pdf