Wide range doping controllability of p-type GaN films prepared via pulsed sputtering

Abstract

The growth of Mg-doped GaN over a wide doping range is demonstrated via pulsed sputtering deposition (PSD). All samples show p-type conductivity without any post-growth annealing, and their room temperature (RT) hole concentration can be controlled for as much as two orders of magnitude from 2.8 × 1016 cm−3 to 2.7 × 1018 cm−3. No apparent structural degradation is observed, even for the most heavily Mg-doped sample with an RT hole concentration of 2.7 × 1018 cm−3. The compensation ratio is lower than 10% for the heavily Mg-doped samples, which explains the high conductivity of PSD-grown p-type GaN. These results indicate the strong potential of PSD for the growth of high-quality p-type GaN and its application to p–n junction devices.