Fabrication of a High-Power Gan Metal Semiconductor Field-Effect Transistor

Abstract

ABSTRACTA high-power metal semiconductor field-effect transistor (MESFET) for operating at a very large-current using GaN is reported for the first time. GaN was grown by metalorganic chemical vapor deposition (MOCVD). Sapphire substrates were used for GaN growth. A GaN MESFET with a large size was fabricated. Multi-finger gates were used for large-current operation. The total gate width was 8 cm and the gate length was 2 νm. The electrode materials of the source and the drain were Al/Ti/Au and the schottky electrodes were Pt/Au. The gate, source, and drain were isolated using SiO2. An FET structure was fabricated using a dry-etching technique. Multi-electrode structures were also fabricated using SiO2 for isolating the source, drain, and gate electrodes, respectively. The FET was operated at a current of over 5 A. The breakdown voltage was over 500 V. The transconductance (gm) was about 12 mS/mm. The pinch-off voltage was about -8 V. We confirmed that this GaN MESFET can also be operated at a current of 10 A.