A GaN RB-MISHEMT with a Schottky-MIS hybrid drain and An Al_(0-0.50)Ga_(1-0.50)N/GaN heterojunction

摘要

In this work, a GaN reverse-blocking (RB) MISHEMT with a Schottky-MIS hybrid drain and a thin-upward-graded-Al0-0.50Ga1-0.50N/GaN heterojunction is proposed and investigated by TCAD Sentaurus. The Schottky-MIS hybrid structure incorporated in the drain terminal of the proposed device is employed to provide the device with decent reverse-blocking capability. Moreover, the double-electron barrier from the Schottky-MIS hybrid drain can also effectively suppress the drain-induced barrier lowering (DIBL) in devices with short MIS-controlled channel, subsequently enabling the device to exhibit more stable and less geometry-dependent characteristic, and much shorter reverse recovery time (similar to ns) than the conventional RB-MISHEMT. To reduce the turn-on voltage of the Schottky-contact structure, a thin-upward-graded-Al0-0.50Ga1-0.50N barrier layer (the 10 nm Al0-0.50Ga1-0.50N barrier layer) is employed to replace the conventional thick fixed-Aluminum-role AlGaN barrier layer (the 25 nm Al0.23Ga0.77N barrier layer), subsequently causing the proposed device possessing a low drain offset voltage of 0.60 V and low on-state voltage of 1.80 V.