Kinetic Monte Carlo simulation of the nitridation of the GaAs (100) surfaces

TL;DR

This study uses kinetic Monte Carlo simulations to investigate how nitrogen atoms adsorb and interact with GaAs (100) surfaces, revealing preferences for unoccupied sites and the dynamics of N island formation during epitaxial growth.

Contribution

It provides the first systematic theoretical analysis of nitrogen adsorption and island formation on GaAs (100) surfaces using kinetic Monte Carlo methods.

Findings

N atoms prefer unoccupied sites near As dimers

N pushes As dimers out, causing anion exchange

Insights into N island formation during III-Nitride growth

Abstract

We present, in this work, our preliminary results of a systematic theoretical study of the adsorption of N over As-terminated GaAs (100) (2$\times$1) surfaces. We analyzed the changes in the bond-lenghts, bond-angles and the energetics involved before and after deposition. Our results show that the N-atoms will prefer the unoccupied sites of the surface, close to the As dimer. The presence of the N pushes the As dimer out of the surface, leading to the anion exchange between the N and As atoms. Based on our results, we discussed about the kinetics of the N islands formation during epitaxial growth of the III-Nitrides.