Fabrication of 4H-SiC MESFETs on conducting substrates and analysis of their premature breakdown

초록

We report on the effects of the thickness of the buffer layer on the power performance of silicon carbide (SiC) Metal Semiconductor Field Effect Transistors (MESFETs). The 0.5-mum gate-length 4H-SiC MESFET demonstrated on a conducting SiC substrate showed a maximum drain current of 300 mA/mm and a maximum transconductance of 24 mS/mm. The device had an f(T) of 3.2 GHz and an f(max) of 12.4 GHz at V-ds 25 V and V-gs = -4 V. The peak CW output power was 25.3 dBm (0.85 W/mm) with a 34.5% power added efficiency (class A operation) at 2 GHz. The low power-density was from the low breakdown voltage. The simulation results showed the power limitation came from the p-buffer layer on top of the n-type conducting substrate.

키워드