Epitaxial growth of compound semiconductors using lattice-tuned domain-matching epitaxy
AssigneeUltratech, Inc.
InventorsAndrew M. Hawryluk, Daniel Stearns
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Abstract
A method of epitaxially growing a final film using a crystalline substrate wherein the final film cannot be grown directly on the substrate surface is disclosed. The method includes forming a transition layer on the upper surface of the substrate. The transition layer has a lattice spacing that varies between its lower and upper surfaces. The lattice spacing at the lower surface matches the lattice spacing of the substrate to within a first lattice mismatch of 7%. The lattice spacing at the upper surface matches the lattice spacing of the final film to within a second lattice mismatch of 7%. The method also includes forming the final film on the upper surface of the transition layer.
Claims44
A method of epitaxially growing a desired film having a lattice spacing aF using a crystalline substrate having an upper surface and a lattice spacing as, the method comprising:
- forming on the upper surface of the substrate at least one transition layer having a lower surface, an upper surface, a thickness h, and a lattice spacing aT(z) that varies between the lower and upper surfaces such that the lattice spacing aT(0) at the lower surface satisfies m·aT(0)=n·as to within a first lattice mismatch of 7%, where n, m are integers, and the lattice spacing aT(h) at the upper surface satisfies the relationship i·aT(h)=j·aF to within a second lattice mismatch of within 7%, where i, j are integers;
- and
- forming the desired film on the upper surface of the transition layer.
A method of forming a template substrate for growing a desired film having a lattice spacing aF, the method comprising:
- forming on an upper surface of a crystalline substrate having a lattice spacing as at least one transition layer having a lower surface, an upper surface, a thickness h, and a lattice spacing aT(z) that varies between the lower and upper surfaces of the at least one transition layer such that the lattice spacing aT(0) at the lower surface satisfies the relationship m·aT(0)=n·as to within a first lattice mismatch of 7%, where n, m are integers, and the lattice spacing aT(h) at the upper surface of the at least one transition layer satisfies the relationship i·aT(h)=j·aF to within a second lattice mismatch of 7%, where i, j are integers.
A method of epitaxially growing a final film using a crystalline substrate having a surface and a substrate lattice spacing, the method comprising:
- forming on the substrate surface at least one transition layer having a lattice spacing that varies between the lower and upper surfaces such that the lattice spacing at the lower surface matches the substrate lattice spacing to within a first lattice mismatch of 7% and the lattice spacing at the upper surface matches a lattice spacing of the final film to within a second lattice mismatch of 7%;
- and
- forming the final film on the upper surface of the transition layer.
Dependencies are inferred from the claim text.