Gate reliability enhancement of p-GaN gate HEMTs with oxygen compensation technique

Improved p-GaN gate reliability is achieved through a simple oxygen compensation technique (OCT), which involves oxygen plasma treatment after gate opening and subsequential wet etching. The OCT compensates for the Mg acceptors near the p-GaN surface, leading to an extended depletion region under the same gate bias and thus reducing the electric field. Furthermore, the Schottky barrier height also increases by OCT. Consequently, suppressed gate leakage current and enlarged gate breakdown voltage are achieved. Notably, the maximum applicable gate bias also increases from 4 V to 8.1 V for a 10-year lifetime at a failure rate of 1%.