Enhancement-mode GaN/AlGaN p-channel field effect transistors with ID > 110 mA/mm achieved through source/drain tunnel junction contacts

In this Letter, we present enhancement-mode (E-mode) GaN/AlGaN p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) with excellent performance by introduction of polarization induced tunnel junctions to enhance the source/drain (S/D) contacts and lateral current spreading in the access regions. The S/D contact resistance (RC) of 19.84 Ω·mm at voltage of 5 V was obtained. The fabricated GaN p-MOSFET has a threshold voltage (VTH) of −0.86 V, a high drain current (ID) up to 115 mA/mm, a low on-resistance (Ron) of 52.6 Ω·mm, and an on/off current ratio (ION/IOFF) of 7.2 × 104. The monolithically fabricated GaN power high electron mobility transistor shows a breakdown voltage (BV) more than 1700 V. The proposed technology of GaN p-MOSFETs was promising in the applications of GaN logic and drivers for all-GaN monolithic power integrated circuits.