High voltage AlGaN/GaN HFET employing low taper angle field-plate for stable forward blocking capability

A new high voltage AlGaN/GaN heterojuction field effect transistor (HFET) employing low taper angle field-plate (LTA-FP) has been proposed and verified experimentally to achieve stable forward blocking capability with low leakage current. Proposed device with a LTA-FP of 10 degrees, fabricated by adopting a new taper etching process, exhibits stable forward blocking capability with low leakage current (2 orders of magnitude smaller) under repetitive high voltage stress, whereas the conventional device with steep FP of 70 degree shows that unstable behavior under the same stress. These experimental results indicate that the proposed LTA-FP suppresses the electric field concentration at the gate edge successfully and is an effective approach to secure the stable blocking characteristics of GaN based high voltage devices.