Self-aligned p-channel MISFET with a low-temperature-grown GaAs gate insulator

A new p-channel GaAs metal-insulator-semiconductor field-effect transistor (MISFET) using low-temperature-grown (LTG) GaAs as the gate insulator is demonstrated. Neither the GaAs conducting channel nor the gate insulator was doped, and a Be self-aligned implant was used to lower the source and drain series resistance. For a MISFET with a 1.5-μm gate length, the transconductance is 22 mS/mm and the maximum drain current is 120 mA/mm obtained at -8 V of gate bias. The measured unity-current-gain cut-off frequency f_T is 2.0 GHz.