Bufferless GaN‐Based MOSFETs Fabricated on GaN‐on‐Insulator Wafer

Abstract

Three types of bufferless GaN‐based FETs are fabricated on GaN‐on‐insulator (GaNOI) wafer: i) recessed‐gate AlGaN/GaN MOSFET with threshold voltage (Vth) of 4 V; ii) AlGaN/GaN nanowire gate‐all‐around (GAA) MOSFET with Vth of −2 V; and iii) GaN nanowire GAA‐MOSFET with Vth of 3.5 V. These devices are characterized and compared. The nanowire GAA‐MOSFET can be easily fabricated by simply removing buried oxide layer of GaNOI wafer. The recessed‐gate AlGaN/GaN MOSFET presents poor on‐current characteristic. On the other hand, the nanowire GAA‐MOSFETs show improved on‐current, reduced subthreshold swing (SS), good pinch‐off characteristics, and negligible current collapse phenomenon.