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

Three types of bufferless GaN-based FETs are fabricated on GaN-on-insulator (GaNOI) wafer: i) recessed-gate AlGaN/GaN MOSFET with threshold voltage (V-th) of 4V; ii) AlGaN/GaN nanowire gate-all-around (GAA) MOSFET with V-th of -2V; and iii) GaN nanowire GAA-MOSFET with V-th of 3.5V. 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.