Impact of Mg out-diffusion and activation on the p-GaN gate HEMT device performance

The p-GaN gate HEMT device architecture is a prime contender for normally-off GaN power transistors. In this work the growth parameters of the Mg doped p-type GaN layer are varied and the impact of Mg out-diffusion and Mg activation on the main HEMT device parameters is studied. The Mg chemical concentration is optimized together with the Mg active concentration to obtain improved device performance. Enhancement mode 36 mm p-GaN gate power transistors have been realized, featuring a threshold voltage of 2.1 V and a Ron of 150 ma.