Molecular dynamics simulation of the scratching process of GaAs with different crystal orientations

H Huang and C Jiang and R Gao and JX Jiang, JOURNAL OF MOLECULAR MODELING, 30, 189 (2024).

DOI: 10.1007/s00894-024-05981-6

ContextIn order to further improve the manufacturing technology of resonator facet of GaAs (gallium arsenide)-based laser, the scratching process of GaAs was simulated by molecular dynamics. Models of GaAs crystals with different orientations, including GaAs 100, GaAs 110, and GaAs 111, were generated, followed by scratch simulations on these models. The surface characteristics of scratches, damage width, subsurface damage, stack height, and the distribution and activity characteristics of dislocations were analyzed based on the simulation results. The results show that there are obvious anisotropy in the deformation of different crystal orientation during the scratching process of GaAs. Surface features, damage width, subsurface damage, and dislocation dynamics during scraping in GaAs crystals strongly depend on crystal orientation. It was also observed that GaAs exhibits distinct characteristics of dislocation activity during the scratching process, depending on its crystal orientation. In addition, GaAs 110 crystal direction has the smallest maximum damage width and subsurface damage depth. The maximum of maximum damage width is in GaAs 100 crystal direction, and the maximum subsurface damage depth is in GaAs 111 crystal direction. In addition, the stacking height is maximum when GaAs 100 is scraped and minimum when GaAs 110 is scraped.MethodsThe engraving quality of GaAs materials was investigated utilizing the LAMMPS software through molecular dynamics simulations, while observations were facilitated using the OVITO software. The MD simulation was conducted employing the NPT ensemble, with the temperature fixed at 300 K. A time step of 2 fs was utilized, and the total duration of the MD simulation spanned 600 ps.

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