摘要
GaN metal-oxide-semiconductor field-effect transistors （MOSFETs） on AIGaN/GaN heterostructure with a recess gate were fabricated and characterized. The device showed good pinch-off characteristics and a maximum field-effect mobility of 145.2 cm2.V-1.s-1. The effects of etching gas of CI2 and SiCI4 were investigated in the gate recess process. SiCI4-etched devices showed higher channel mobility and lower threshold voltage. Atomic force microscope measurement was done to investigate the etching profile with different etching protection mask. Compared with photoresist, SiO2- masked sample showed lower surface roughness and better profile with stepper sidewall and weaker trenching effect resulting in higher channel mobility in the MOSFET.
GaN metal-oxide-semiconductor field-effect transistors （MOSFETs） on AIGaN/GaN heterostructure with a recess gate were fabricated and characterized. The device showed good pinch-off characteristics and a maximum field-effect mobility of 145.2 cm2.V-1.s-1. The effects of etching gas of CI2 and SiCI4 were investigated in the gate recess process. SiCI4-etched devices showed higher channel mobility and lower threshold voltage. Atomic force microscope measurement was done to investigate the etching profile with different etching protection mask. Compared with photoresist, SiO2- masked sample showed lower surface roughness and better profile with stepper sidewall and weaker trenching effect resulting in higher channel mobility in the MOSFET.
