Investigation of critical parameters influencing the homoepitaxial growth of GaN thin films via molecular dynamics simulation

YS Wu and CP Chen and JM Zhang and JH Li, COMPUTATIONAL MATERIALS SCIENCE, 250, 113730 (2025).

DOI: 10.1016/j.commatsci.2025.113730

The mechanisms in which GaN substrate surfaces, substrate temperatures, atomic incident angles, and Ga/N ratios influence the growth of GaN films during the homoepitaxial growth of GaN on GaN substrates have been investigated using molecular dynamics simulations. Films grown on the (0001) Ga-terminated GaN surface exhibit superior surface morphology and crystal quality compared to those grown on the (000-1) N-terminated GaN surface. Increasing the substrate temperature enhances the surface kinetics of Ga and N atoms, contributing to the growth of GaN films with improved surface morphology and crystallinity. Within the critical range of atomic incident angles, the surface roughness of the film is minimally affected, while the crystal quality shows a significant improvement. An increase in the Ga/N ratios results in a reduction in surface roughness and an enhancement in crystal quality. In conclusion, superior surface morphology and crystal quality can be achieved during epitaxial growth on (0001) Ga-terminated GaN surfaces when the atomic incident angles are within the critical range, the Ga/N ratio is high, and the substrate temperature is elevated. These discoveries offer valuable insights for preparing high-quality GaN thin films via molecular beam epitaxy and inform the design of the angle between the beam source furnace and the substrate in the device.

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