Ge-GaN deposition: An assistant kMC model

Abstract

The present work provides a parametric simulation tool to assist the experimental deposition of GaN and Ge-GaN material. For this purpose, a kinetic Monte Carlo (kMC) model was developed and implemented to simulate the deposition, diffusion, and desorption of Ge, Ga, and N and subsequent material growth on GaN (0001). The kMC is a Monte Carlo algorithm that simulates the dynamics of a given on-the-lattice system by computing on-the-fly every event rate. In the present model, the deposition rates were computed by means of the collision theory and the diffusion and desorption rates were calculated with the usual Arrhenius form based on knowledge of the activation energies and the local energy configuration. Ge diffusion energies as well as experimental deposition conditions were simulated to investigate their impact on the resulting Ge-GaN layers. Proposed kMC model outcomes, which are consistent with the observed experimental results, are discussed in detail and conclusions are provided.