Electrical Performance of Gate-recessed AlGaN/GaN MOS-HEMTs Fabricated using Photoelectrochemical Method

Abstract

Gate-recessed AlGaN/GaN MOS-HEMTs were fabricated using a photoelectrochemical (PEC) method to form the recessed structure and to directly grow gate insulator on the recessed surface. The resulting devices exhibited better performances than conventional one without gate recess, including a saturation drain-source current of 642 mA/mm, and an off-state breakdown voltage larger than -100V. The normalized noise power spectra of both kinds of devices at the saturation region were well-fitted by the 1/f law and the Hooge's coefficient α in both devices was about 10−4, demonstrating that PEC wet etching is an effective way to achieve a damage-free surface and to improve the DC characteristics of the MOS-HEMTs.