The growth mechanism of GaN grown by hydride vapor phase epitaxy in N 2 and H 2 carrier gas

Abstract

This paper investigates the growth mechanism of GaN for the hydride vapor phase epitaxy (HVPE) process in the N 2 and H 2 carrier gas ambients. Differences are observed between the surface morphologies of GaN films grown in N 2 carrier gas and those grown in H 2 carrier gas. It is determined that the GaN growth direction and growth rate are both affected by H 2 flow rate. In N 2 ambient, the {1 1 ̄ 0 1} facet is stable, because of the N-polarity and high dangling bond density (DB) of {1 1 ̄ 0 1} facet. On the other hand, in H 2 ambient, and the {1 1 ̄ 0 0} facet becomes stable. In this paper, this phenomenon will be explained by the atomic configuration model of the GaN wurtzite structure.