Improved threshold voltage stability for GaN p-channel field effect transistors by hydrogen plasma treatment

Abstract This work proposes a novel gate stack with hydrogen (H) plasma treatment to improve the stability of p-channel field effect transistors (p-FETs). The threshold voltage (VTH) of this device is −4.818 V, achieving normally-off operation, with exhibiting an Ion/Ioff ratio of 106 and a low off-state leakage current of -10−7 mA/mm at VGS=2V. The H plasma-treated gate stack significantly stabilizes the VTH of GaN p-FETs, exhibiting minimal variations of 0.136 V and 0.15 V under negative (-5 V) and positive (5 V) gate voltages, respectively. H plasma treatment technology optimizes the sub-gate interface and enhances the threshold voltage stability of the device, guaranteeing the stable application of p-FETs in logic circuits.