通过低温氮化处理有效抑制AlGaN/GaN MISHEMT中的电流崩塌

We successfully demonstrated a 72% reduction in current collapse under high-field driving conditions ( V_ D =300 V) for AlGaN/GaN MISHEMT using low-temperature supercritical fluid nitridation (SCFN) treatment at 180~^ C for 1 h. A significant improvement in the off-state ( V_ G= -10 V) gate leakage current was observed in MISHEMT with SCFN treatment, resulting in a high breakdown voltage (BV) capability of up to V_ D=710 V (at 1~ A/mm), compared to only V_ D=110 V without SCFN. Furthermore, in terms of characteristics, the device was improved with a 4.6% increase in maximum drain current ( I_ D, ), a 2.9% increase in maximum transconductance ( G_ m, ), and an 11.1% decrease in drain-source on resistance [ R_ DS (on)]. These improvements can be attributed to the repairs of dangling bonds on the AlGaN surface and the elimination of the Al2O3/AlGaN interface traps, which collectively lead to improved performance and stability. Based on the abovementioned results, the X-ray photoelectron spectroscopy (XPS), conduction band edge of defect state density ( D_ it ), and gate leakage trap-related hopping conduction mechanism were analyzed to explain the phenomenon.