Highly P-Typed Mg-Doped GaN Films Grown with GaN Buffer Layers

Mg-doped GaN films were grown with GaN buffer layers on a sapphire substrate. Hall-effect measurement of as-grown GaN films showed that the hole concentration was 2×10 15 /cm 3 , the hole mobility was 9 cm 2 /V·s and the resistivity was 320 Ω·cm at room temperature. After the low-energy electron-beam irradiation (LEEBI) treatment, each value became 3×10 18 /cm 3 , 9 cm 2 /V·s and 0.2 Ω·cm at room temperature, respectively. This value of the hole concentration is the highest ever reported for the p-type GaN films and that of the resistivity is the lowest.