Photoelectrochemical (PEC) etching is a promising technology for fabricating GaN devices with low damage. In the simple contactless PEC (CL–PEC) etching process that includes K2S2O8 in the electrolyte as an oxidizing agent, a sample is dipped into the electrolyte under UV irradiation. In this study, we applied CL–PEC to the gate-recess process of GaN HEMTs on an SiC substrate. The etching depth of the recess showed considerable reproducibility by the self-termination feature, and the residual AlGaN layer thickness was approximately 5 nm. The Schottky gate HEMTs with a recessed structure showed the normally off characteristics, and the Vth value was +0.4 V with a standard deviation of ±3.8 mV.
Fabrication of Recessed Structures for GaN HEMTs by a Simple Wet Etching ProcessTaketomo Sato, Hokkaido UniversityFumimasa Horikiri, Sciocs Company LimitedNoboru Fukuhara, SCIOCS Company Ltd.Masachika Toguchi, Hokkaido UniversityKazuki Miwa, Hokkaido UniversityYoshinobu Narita, Sciocs Company LimitedOsamu Ichikawa, SCIOCS Company Ltd.Ryota Isono, SCIOCS Company Ltd.Takeshi Tanaka, SCIOCS Company Ltd.Download Paper