(Received July 24, 1991; accepted for publication August 20, 1991)
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 2×1015/cm3, the hole mobility was 9 cm2/V·s and the resistivity was 320 Ω·cm at room temperature. After the low-energy electron-beam irradiation (LEEBI) treatment, each value became 3×1018/cm3, 9 cm2/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.
KEYWORDS:Hall-effect measurement, Mg-doped GaN, hole concentration, hole mobility, resistivity, buffer layer