Reduction of Backgating in GaAs SISFET’s with a Low-Temperature Buffer

A low-temperature MBE-grown buffer layer has been used to reduce backgating in GaAs/AlGaAs semiconductor-insulator-semiconductor FET’s (SISFET’s). Comparison with a control wafer having no low-temperature buffer (LTB) reveals an improvement in backgating threshold voltage by a factor of 3, improvement in output conductance and short-channel characteristics, and no significant change in threshold voltage, threshold-voltage spread, and microwave characteristics. The FET’s with LTB exhibited increased sensitivity, at 80 K, to trapping of hot electrons. © 1991 IEEE