US 4,821,093 A · Dual channel high electron mobility field effect transistor

Abstract

A multi-terminal Group III-V semiconductor high electron mobility field effect transistor comprised of a sandwich of molecular beam epitaxially grown layers and including two high mobility charge flow channels in respective two dimensional electron gas regions implemented, for example, by at least one doped layer of aluminum gallium arsenide adjacent an undoped gallium arsenide layer separated by a heterojunction. A pair of opposing two dimensional electron gas (2DEG) regions are generated in the layer of undoped gallium arsenide by the bending of the energy levels of the semiconductor materials. Charge flow occurs in a unidirectional fashion from one channel to the other in the common undoped gallium arsenide layer under the control of an electric field applied transversely through the structure by means of a top gate electrode and a bottom field plate electrode. Alternatively, the source voltage can be increased until the requisite amount of energy has been provided for the electrons to become "hot" enough to transfer from one channel to the other, in which case a lower biasing contact is not required. Relatively high signal isolation is inherently provided thereby between a pair of output terminals or signal ports. The device, moreover, is operable as a high speed signal coupler, amplifier, mixer as well as a photoelectric detector/amplifier.

Claims32

Dependent claims

A high electron mobility field effect semiconductor device, comprising, in combination:

a first body of undoped semiconductor material;
second and third bodies of semiconductor material located on opposite sides of said first body of undoped material, said second and third bodies of semiconductor material having respective energy bandgaps each greater than the energy bandgap of said first body of undoped material, and separated therefrom by respective first and second heterojunctions formed at the interfaces thereof, one of said second and third bodies of semiconductor material providing a source of charge carriers for diffusing charge carriers into said first body of material, a portion of said diffused carriers being confined at said first and second heterojunctions into respective first and second two dimensional electron gas (2 DEG) regions;
fourth and fifth bodies of semiconductor material, doped to facilitate Ohmic contact adjacent respectively said second and third bodies of semiconductor material, said fourth and fifth bodies forming respective outer layers of said device;
and
first and second sets of electrodes on the exterior of said device for modulating the flow of charge in respective first and second two dimensional electron gas regions underlying said sets of electrodes;
said first set of electrodes having source, gate, and drain electrodes disposed upon said fourth body of semiconductor material, and said second set of electrodes having at least source and drain electrodes disposed on said fifth body of semiconductor material.

3 more elements

Dependencies are inferred from the claim text.

Dual channel high electron mobility field effect transistor

Life of this patent

Dual channel high electron mobility field effect transistor

Life of this patent

Abstract

Claims32