Growth of scandium doped GaN by MOVPE

Abstract

Scandium (Sc) doped GaN layers (GaN:Sc) were grown on SiN treated sapphire substrate by atmospheric pressure metal-organic vapor phase epitaxy (AP-MOVPE) using Tris(cyclopentadienyl)scandium (Cp3Sc) as a scandium precursor. Standard growth conditions of GaN were used with varying Cp3Sc flow rate up to 1000 sccm. The growth was in situ monitored by laser reflectometry. GaN coalescence process is significantly influenced by the presence of Cp 3Sc. Sc incorporation in GaN is confirmed by secondary ion mass spectrometry (SIMS) measurements. Electron concentration and mobility variations versus Cp3Sc flow rate were studied by room temperature Hall effect measurements. All samples showed n type conductivity. High resolution X-ray diffraction (HRXRD) results showed a slight broadening of rocking curves around symmetric (00.2) reflexions for Sc doped GaN layers with increasing Cp 3Sc flow rate. Room temperature photoluminescence (PL) showed a quenching of ultraviolet near band edge emission (UV) by increasing Sc doping level. © 2013 Elsevier Ltd. All rights reserved.