MOCVD Growth of Cubic GaN on 3C-SiC Deposited on Si(100) Substrates

摘要

The growth of cubic GaN on 3C-SiC/Si(100) by metal-organic chemical vapor deposition (MOCVD) under various growth temperatures, thicknesses of 3C-SiC, and V/III ratios was studied. The fractions of cubic and hexagonal phases in the films were estimated from the integrated x-ray diffraction intensities of the cubic (002) and hexagonal (10110) planes. A smooth SiC layer, a high growth temperature, and a moderate V/III ratio are three key factors for the nucleation of the cubic phase and its subsequent growth. hexagonal GaN with its c-axis perpendicular to the substrate preferentially grows at the low temperature of 750degC. The inclusion of the cubic phase increases with increasing growth temperature. The optimum growth conditions for dominant cubic GaN formation were a growth temperature of 950degC, a 1.5 #mu#m thick SiC layer, and a V/III ratio of 1500. With these growth conditions, a cubic GaN layer with the cubic component of 91% was obtained.