Enhancement mode operation and ultraviolet responsivity of n-channel GaN metal-insulator-semiconductor field effect transistor with schottky barrier source and drain

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 V_DS = 10 V, and the drain leakage current density of less than In A/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 V_DS= 5V.