New field plate structure for suppression of leakage current of AlGaN/GaN high electron mobility transistors

A new field plate structure for suppressing the leakage current of AlGaN/GaN high electron mobility transistors (HEMTs) is proposed. The proposed field plate structure consists of a gate field plate and an additional field plate. We fabricated AlGaN/GaN HEMTs employing the new field plate structure. The proposed field plate expands the depletion region and reduces the electric field concentration at the gate edge compared with the conventional single field plate. Experimental results show that the leakage current of the proposed device is 287.9 mu A/mm, which is 42% less than that of a conventional one without field plate.