Offset channel insulated gate field-effect transistors

Abstract

We report a new insulated gate field-effect transistor, which has a conducting channel created by the band bending and band edge discontinuity at a selectively doped Al0.3Ga0.7As/GaAs interface rather than at the insulator-semiconductor interface. The device can be operated both in the depletion mode and in the enhancement mode with a dc transconductance of 18 mmho/mm in both cases (gate length = 5.2 μm). The gate electrode can sustain a positive voltage greater than 2 V. Preliminary results indicate that the idea of offset channel can be of great importance for realizing ultrahigh speed transistors.