Drastic Reduction of Dislocation Density in Semipolar (1122) GaN Stripe Crystal on Si Substrate by Dual Selective Metal–Organic Vapor Phase Epitaxy

Abstract

A drastic reduction of the dislocation density in a semipolar (1122) GaN stripe on a patterned Si substrate was achieved by the two-step selective growth of a GaN stripe. After depositing a SiO2 mask on the (1122) and (0001) faces of a GaN stripe grown on a (113) Si substrate, GaN was regrown only on the (1122) face. The dislocation density estimated from the dark-spot density in a cathodoluminescence (CL) image greatly decreased from 4.0×108 to 1.0×105/cm2 in the regrowth region. A transmission electron microscopy (TEM) image also verified that there were no dislocations at the regrowth interfaces.