Evaluation of heteroepitaxially grown semipolar {20-21} GaN on patterned sapphire substrate

Abstract

Semipolar {20-21} GaN layers were grown on {22-43} patterned sapphire substrates by metal-organic vapor phase epitaxy using a two-step growth method. We succeeded in suppressing -c-plane growth at growth temperatures of 1,000 and 900°C for the first and second steps, respectively; the resulting structure exhibited a large reduction in the number of stacking faults upon optimizing the growth conditions. Photoluminescence measurements showed an increase in the near-band-edge emission and a decrease in deep-center emission when the two-step growth was performed at higher V/III ratio. © 2014 Springer International Publishing.