A Comparison of GaN Epilayers with Multiple Buffer Layers and with a Single Buffer Layer Grown on Si(111) Studied by HRXRD and RBS/Channeling

摘要

@@ Two hexagonal GaN epilayers (samples A and B) with multiple buffer layers and single buffer layer are grown on Si (111) by metal-organic vapour phase epitaxy (MOVPE).From the results of Rutherford backscattering (RBS)/channeling and high resolution x-ray diffraction (HRXRD),we obtain the lattice constant (a and c) of two GaN epilayers (aA = 0.3190 nm,cA = 0.5184 nm and aB = 0.3192 nm,cB = 0.5179 nm),the crystal quality of two GaN epilayers ( XminA = 4.87%,XminB=7.35% along<1(2)13> axis) and the tetragonal distortion eT of the two samples along depth (sample A is nearly fully relaxed,sample B is not relaxed enough).