Reduction of backgating in GaAs SISFET's with a low-temperature buffer

The use of a low-temperature molecular beam epitaxy (MBE)-grown buffer layer to reduce backgating in GaAs/AlGaAs semiconductor-insulator-semiconductor FETs (SISFETs) is discussed. 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 FETs with LTB exhibited increased sensitivity, at 80 K, to trapping of hot electrons.>