SiC backside source grounding process for AlGaN/GaN HEMT by physical dicing method

Abstract

A physical dicing method for realising backside source grounding is first proposed for high-power microwave AlGaN/GaN high electron mobility transistors (HEMTs) on 4-inch 477 µm-thick silicon carbide (SiC) substrates. The successful implementation of the dicing-assisted source grounding technology in the processing of HEMTs is confirmed by DC and RF characterisation. When biased at 30 V, a 10 GHz output power density of 9.18 W/mm is achieved with an associated gain of 9.6 dB and power added efficiency of 50% for a 2×(200×0.5) µm2 AlGaN/GaN HEMT with backside source grounding.