Non‐volatile memory operation in normally‐off GaN MOS heterostructure field effect transistors with thin AlGaN barrier

Abstract

Normally-off AlGaN/GaN metal-oxide-semiconductor heterostructure field effect transistors have been fabricated and characterised for non-volatile memory operation. 2 nm-thickness AlGaN barrier layer was obtained by gate recess process using inductively-coupled-plasma etching. The device was set to a program state by applying positive gate bias which induced the positive shift of threshold voltage and this shift was switched back to the original value by applying negative gate bias. The threshold voltage shift was 3.6 V between the program and the erase states. The retention characteristics were stable for over 105 s. The device characteristics were not degraded after 103 cycles of program/erase operations.