Polycrystalline diamond normally-off MESFET passivated by a MoO3 layer

Abstract

The normally-off hydrogen-terminated diamond metal–semiconductor field effect transistors (MESFETs) with a MoO3 passivation layer were fabricated on the CVD grown polycrystalline diamond substrate. The characteristics of the device at room temperature and 100 °C, 150 °C and 200 °C were investigated. The device with a 2-μm gate shows a threshold voltage of −0.38 V, the maximum output current of 35 mA/mm and the transconductance of 17.4 mS/mm. The device can still work normally until 150 °C, which shows great potential to be used in high temperature in the future.