Dislocation density reduction in gallium arsenide on silicon heterostructures
AssigneeKopin Corporation
InventorsJagdish Narayan, John C. C. Fan
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Abstract
A method of forming gallium arsenide on silicon heterostructure including the use of strained layer superlattices in combination with rapid thermal annealing to achieve a reduced threading dislocation density in the epilayers. Strain energy within the superlattices causes threading dislocations to bend, preventing propagation through the superlattices to the epilayer. Rapid thermal annealing causes extensive realignment and annihilation of dislocations of opposite Burgers vectors and a further reduction of threading dislocations in the epilayer.
Claims20
A method of forming a gallium arsenide on silicon heterostructure comprising the steps of:
- forming a first gallium arsenide layer over a silicon substrate;
- forming a first strained layer superlattice over the first gallium arsenide layer, the strained layer superlattice comprising alternating layers of a first material and second material;
- forming an upper gallium arsenide over the first strained layer superlattice to form a layered structure;
- and
- subjecting the formed structure to rapid thermal annealing for about two minutes or less.
A method of forming a gallium arsenide on silicon heterostructure comprising the steps of:
- forming a first gallium arsenide layer over a silicon substrate;
- forming a strained layer superlattice structure over the first gallium arsenide layer, the strained layer superlattice structure comprising a plurality of superlattices in which each superlattice includes alternating layers of In.sub.x Ga.sub.1-x As and gallium arsenide;
- forming an upper galium arsenide layer over the first strained layer superlattice structure;
- and
- subjecting the formed structure to rapid thermal annealing for about two minutes of less.
A method of forming a gallium arsenide on silicon heterostructure comprising:
- forming a first gallium arsenide layer over a substrate;
- forming a first strained layer superlattice over the first gallium arsenide layer, the strained layer superlattice comprising alternating layers of a first material and a second material;
- forming an upper gallium arsenide layer over the first strained layer superlattice to form a layered structure;
- and
- heating the formed structure for a period of time in the range of 10 seconds to 60 seconds to anneal the structure.
Dependencies are inferred from the claim text.