Characterization of n-type and p-type GaN layers grown on free-standing GaN substrates

Abstract

Electrical characterization of low-doped n-type and p-type GaN layers grown by metal-organic vapor phase epitaxy are presented. The GaN layers were grown on hydride-vapor-phase-epitaxy-grown free-standing GaN substrates. For n-type GaN, the impact of electron trap on electrical characterization is discussed. Charging of trap in a depletion layer affects C-V characteristics. Correction is needed for depth profiling of net donor concentration. For p-type GaN, hole mobility for various Mg doping concentrations at various temperatures are presented. At 300 K, 33 cm2/Vs is obtained for p-type GaN with Mg doping concentration of mid 1016 cm−3.