Epitaxial indium-gallium-arsenide phosphide layer on lattice-matched indium-phosphide substrate and devices
AssigneeVarian Associates, Inc.
InventorGeorge A. Antypas
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Abstract
An epitaxial layer of a quaternary III-V alloy of Ga, In, As, and P has its constituents proportioned for lattice matching to a substrate having a lattice constant falling within the range of 5.45 to 6.05 A. In addition, the constituents of the alloy are proportioned to provide a selected bandgap energy falling within the range of 2.23 to 0.35 electron volts; this corresponds to wavelengths of 0.55 to 3.5 microns. Near perfect lattice matched heterojunctions are provided between the epitaxial layer and the lattice matched substrate; these are useful for providing improved photocathodes and lasers, particularly in the infrared range of wavelengths between 0.8 and 2.0 microns.
Claims9
A lattice-matched heterojunction device comprising:
- a substrate comprising a binary III-V compound of the elements indium and phosphorus and having a lattice constant falling within the range of 5.45 to 6.05 angstrons;
- an epitaxial quaternary III-V layer of the compound InGaAsP joined to the surface of said substrate to form a heterojunction with said substrate, said epitaxial layer having a lattice constant matched to within 0.5 percent of the lattice constant of said substrate to form a lattice matched heterojunction between said substrate and said epitaxial layer.
Dependencies are inferred from the claim text.