Surface Morphology of Ni/GaAs Thin Films Produced by Ion-Plasma Method
Аннотация
In this work, the surface morphology of Ni thin films deposited on GaAs substrates by RF magnetron sputtering was investigated using Atomic Force Microscopy (AFM). Thin films with different thicknesses ($\mathbf{2 5 2 ~ n m}$ and $\mathbf{4 2 0}$ nm) were obtained at deposition times of 6 and 10 minutes. AFM images were recorded at two different scan areas ($\mathbf{3 0} \boldsymbol{\times} \mathbf{3 0} \boldsymbol{\mu} \mathbf{m}^{\mathbf{2}}$ and $\mathbf{5} \times \mathbf{5} \boldsymbol{\mu} \mathbf{m}^{\mathbf{2}}$) to compare global and local surface features. The results revealed that at 252 nm thickness, the films exhibited a rough surface with an RMS roughness of 8.51 nm over the large area, while the smaller area demonstrated a lower RMS value of $\mathbf{2. 4 3 ~ n m}$, indicating smoother local regions. For thicker films (420 nm), the RMS roughness decreased significantly to 3.687 nm (large area) and 2.540 nm (small area), showing enhanced surface smoothness and morphological stability. The observed trend indicates that increasing deposition time and film thickness leads to improved surface uniformity, which is crucial for reducing contact resistance and improving the performance of electronic devices.