Characterization and modeling of the mobility, threshold voltage, and subthreshold swing in p-GaN gate HEMTs at cryogenic temperatures

This study presents a comprehensive investigation of the electrical properties of p-GaN gate HEMT devices under cryogenic operations, spanning a temperature range from 300 K all the way down to 10 K. We report achievement of a low sub-60 mV/dec sub-threshold swing (SS) (33.2 mV/dec at 10 K), a high I-ON/I-OFF ratio (similar to 3.5 x 10(10) at 10 K), and a remarkable I-D,I-max (similar to 358 mA/mm at 10 K) in p-GaN gate HEMTs operating under cryogenic conditions. Furthermore, the mobility, threshold voltage shifts, and SS characteristics at cryogenic temperatures are modeled in p-GaN HEMTs. In summary, p-GaN gate HEMTs are promising for cryogenic applications due to their low SS, high g(m,max), impressive I-ON/IOFF ratio, and substantial I-D,I-max. Furthermore, the modeling achieved in this work can pave the way for future characteristic prediction in p-GaN HEMTs at cryogenic temperatures.