Semipolar (2023) nitrides grown on 3C–SiC/(001) Si substrates

Abstract

Heteroepitaxial growth of GaN buffer layers on 3C–SiC/(001) Si templates (4°-offcut towards [110]) by metalorganic vapour phase epitaxy has been investigated. High-temperature grown Al0.5Ga0.5N/AlN interlayers were employed to produce a single (203) GaN surface orientation. Specular crack-free GaN layers showed undulations along [10] with a root mean square roughness of about 13.5 nm (50 × 50 μm2). The orientation relationship determined by x-ray diffraction (XRD) was found to be [20]GaN ∥[10] and [034]GaN ∥[110]3C − SiC/Si. Low-temperature photoluminescence (PL) and XRD measurements showed the presence of basal-plane stacking faults in the layers. PL measurements of (203) multiple-quantum-well and light-emitting diode structures showed uniform luminescence at about 500 nm emission wavelength. A small peak shift of about 3 nm was observed in the electroluminescence when the current was increased from 5 to 50 mA (25–250 A cm−2).