Enhancement Mode Operation and Ultraviolet Responsivity of n-Channel GaN Metal–Insulator–Semiconductor Field Effect Transistor with Schottky Barrier Source and Drain

Abstract

We investigated the electrical properties and photo-responsive characteristic of enhancement n-channel GaN Schottky barrier metal–insulator–semiconductor field effect transistor (SB-MISFET), which was fabricated on p-GaN grown on silicon substrate. Schottky type source and drain contacts were used to fabricate the enhancement type n-channel GaN MISFET without implantation. The electrical properties of fabricated device with 10 µm gate length and 100 µm width, exhibited a threshold voltage of 2.7 V, the maximum drain current of 1 µA/mm and the maximum transconductance of 0.4 µS/mm at VDS=10 V, and the drain leakage current density of less than 1 nA/mm2. The spectral photo-response characterization exhibits that the cutoff wavelength was 365 nm, and the UV/visible rejection ratio was about 110 near the threshold voltage at VDS=5 V.