MBE growth technology for high quality strained III-V layers
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsFrank J. Grunthaner, John K. Liu, Bruce R. Hancock
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Abstract
III-V films are grown on large automatically perfect terraces of III-V substrates which have a different lattice constant, with temperature and Group II and V arrival rates chosen to give a Group III element stable surface. The growth is pulsed to inhibit Group III metal accumulation to low temperature, and to permit the film to relax to equilibrium. The method of the invention 1) minimizes starting step density on sample surface; 2) deposits InAs and GaAs using an interrupted growth mode (0.25 to 2 mono-layers at a time); 3) maintains the instantaneous surface stoichiometry during growth (As-stable for GaAs, In-stable for InAs); and 4) uses time-resolved RHEED to achieve aspects (1)-14 (3).
Claims16
A method for growing a film comprising multiple high quality strained layers comprising a first III-V compound on a substrate comprising a second III-V compound in molecular beam epitaxy apparatus, said substrate having a sufficiently different lattice parameter than said III-V layer to generate strain in said III-V layers, said method comprising:
- (a) forming a layer of said first III-V material having a slight excess of III-component to maintain a metal-stabilized surface reconstruction while forming about 1/4 to 2 monolayers thick of said first III-V material on said substrate;
- (b) ceasing formation of said layer for a period of time;
- (c) repeating steps (a) and (b) until said film of the desired thickness is grown.
A method for growing a film comprising multiple high quality strained InAs layers on a GaAs substrate in molecular beam epitaxy apparatus comprising:
- (a) forming a layer of InAs material having a slight excess of In to maintain an In-stabilized surface reconstruction while forming about 1/4 to 2 monolayers thick of said InAs material on said substrate;
- (b) ceasing formation of said layer for a period of time;
- (c) repeating steps (a) and (b) until said film of the desired thickness is grown.
Dependencies are inferred from the claim text.