Double heterojunction semiconductor device with injector

Abstract

A semiconductor device including a first semiconductor layer having a low carrier density, a second semiconductor layer on the first semiconductor layer and having a low carrier density, a third semiconductor layer on the second semiconductor layer, a fourth semiconductor layer on the third semiconductor layer and effective to inject holes into the second semiconductor layer through the third semiconductor layer for inducing a channel of, for example, electrons in the second semiconductor layer in proximity to and along the interface between the second and third semiconductor layers, and a pair of ohmic contact regions extending through the second and third semiconductor layers for providing ohmic contact with the second semiconductor layer for permitting modulation of the conductance between the ohmic contact regions when holes, for example, are injected from the fourth semiconductor layer into the second semiconductor layer. The device has double heterojunctions, one between the first and second semiconductor layers and the other between the second and third semiconductor layers, thus providing FET mode and bipolar mode of operation.