Characteristics of a field plate connected to T-shaped gate in AlGaN/GaN HEMTs

An AlGaN/GaN high electron mobility transistor (HEMT) with a T-shaped gate employing a gate-foot-connected field plate is presented. Similar to other devices with gate connected field plates the device described in this paper is a variation of the I-shaped gate with the head of the Tshaped gate attached at the top. The proposed device has a higher breakdown voltage and a lower leakage current due to the attached field plate while maintaining the advantages of the T-shaped gate structure, which are a low gate resistance and a low noise level. In addition, the field plate deposition step during the fabrication process involves a partial covering of the foot of the gate which showed a possibility for a gate length reduction.