Molecular dynamics simulations of AlN deposition on GaN substrate

ABSTRACT

In this work, we investigated the deposition of AlN film on GaN substrate by using molecular dynamics (MD) simulations. The effects of GaN substrate surface, growth temperature, and injected N: Al flux ratio on the growth of AlN film were simulated and studied. Consequently, the deposited AlN film on the (0001) Ga-terminated GaN surface achieves better surface morphology and crystallinity than that on the (000-1) N-terminated GaN surface due to the different diffusion ability of Al and N adatoms on two GaN surfaces. Furthermore, with the increase of growth temperature, the surface morphology and crystallinity of AlN film were improved owing to the enhanced mobility of adatoms. At the optimised injected N: Al flux ratio of 1, comparatively good surface morphology and crystallinity of deposited AlN films were realised. This method lays a foundation for the follow-up real-time study of defects and stress evolution of AlN on GaN and can be applied to film growth of other materials.

GRAPHICAL ABSTRACT

KEYWORDS:

• AlN film
• molecular dynamics
• GaN substrate surface
• surface morphology
• crystallinity

Additional information

Funding

This work was carried out at National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1(A). And this work was supported by the National Natural Science Foundation of China under [grant numbers 51727901, 51476068 and 51402224].