Metalorganic Vapor Phase Epitaxy Growth of a High-Quality GaN/InGaN Single Quantum Well Structure Using a Misoriented SiC Substrate

Abstract

A high-quality GaN/InGaN single quantum well (SQW) structure has been successfully grown using a misoriented 6H–SiC substrate, the face of which is tilted from (0001) toward [1120] by 3.5°, by low pressure metalorganic vapor phase epitaxy (MOVPE). A sharp emission, whose full-width at half maximum (FWHM) was 24.3 meV, from the GaN/InGaN SQW structure was observed at 385 nm in the 77 K photoluminescence spectrum. From the transmission electron microscopy (TEM) analysis, the dislocations in the GaN film grown on the misoriented substrate were bent from the c-direction, and the threading dislocations to the InGaN film on the GaN film were decreased. For the InGaN film grown on the misoriented substrate, only the sharp band edge emission, whose FWHM was 92.3 meV, was observed at 385 nm in the PL spectrum at 77 K. The dislocation density, which was estimated from TEM photographs, in the InGaN film on the GaN film grown on the misoriented substrate was about 5×108 cm-2, which was nearly half of that grown on the (0001) substrate.