Abstract: A high-speed heterostructure planar integrated circuit includes a planar photodetector together with a transistor (either a Modulation-Doped Field Effect Transistor or a lateral p-n-p bipolar transistor). The planar photodetector includes a bottom confinement layer of a wide bandgap material, a heavily doped first conductivity-type buried layer over the bottom confinement layer, a relatively undoped higher index of refraction layer overlying the buried layer, a top confinement layer of wider bandgap material which has a lower index of refraction, a first vertical contact region of first conductivity type which extends downward to make electrical contact with the buried layer, and a second contact region of second conductivity type spaced laterally from the first contact region and extending through the top confinement layer and a portion of the undoped layer.

Abstract: A double heterostructure opto-electronic device capable of both electronic and photonic switching is described.

Abstract: A new solid state field effect bipolar device provides for high current gain and low input capacitance, while avoiding the "punch-through" effects that limit the downward scaling of conventional bipolar and field effect devices. The device typically comprises a metallic (e.g. a metal or silicide) emitter, which makes ohmic contact to a semi-insulator; a channel terminal which contacts an inversion layer formed at the interface between the semi-insulator and a semiconductor depletion region; and a collector, which is the semiconductor bulk. The novel device controls the flow of majority carriers from the emitter into the collector by the biasing action of charge in the inversion channel. The technique can be utilized in making a transistor, photodetector, thyristor, controlled optical emitter, and other devices.