Effects of TMAH Treatment on Device Performance of Normally Off hbox Al 2 hbox O 3 / hbox GaN MOSFET

Normally off hbox Al 2 hbox O 3 hbox / hbox GaN MOSFETs are fabricated by utilizing a simple tetramethylammonium hydroxide (TMAH) treatment as a postgate-recess process. The TMAH-treated device with a gate length of 2.5 mu hbox m exhibited excellent device performances, such as a threshold voltage of 3.5 V, a maximum drain current of 336 mA/mm, and a breakdown voltage of 725 V, along with extremely small gate leakage current of about hbox 10 - 9 Unknown character hbox A / mm at V rm gs = hbox 15 Unknown character hbox V , which is approximately six orders lower in magnitude compared to that of the device without TMAH treatment.