US5221367A
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Strained defect-free epitaxial mismatched heterostructures and method of fabrication
Assignee: International Business Machines Corp
•
Filing: 1988-08-03
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Granted: 1993-06-22
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Expires: 2008-08-03
Abstract
Abstract Heterostructures having a large lattice mismatch between an upper epilayer and a substrate and a method of forming such structures having a thin intermediate layer are disclosed. The strain due to a lattice mismatch between the intermediate layer and the substrate is partially relieved by the formation of edge type dislocations which are localized and photoelectrically inactive. Growth of the intermediate layer is interrupted before it reaches the thickness at which the left over strain is relieved by 60 degree type threading dislocations. The upper epilayer is then grown in an unstrained and defect-free condition upon the intermediate layer where the unstrained lattice constant of the epilayer is about the same as the partially relieved strain lattice constant or the intermediate layer. An unstrained defect-free epilayer of InGaAs has been grown on a GaAs substrate with an intermediate layer 3-10 nm in thickness of InAs. Other large mismatch systems are disclosed, including, GaAs on Si with an intermediate layer of GaInAs.
Inventors
- 👤 Matthew F. Chisholm
- 👤 Peter D. Kirchner
- 👤 Alan C. Warren
- 👤 Jerry M. Woodall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:17
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3221; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; Y; Y10; Y10S; Y10S148/00; Y10S148/072; Y10S148/097; Y10S438/00; Y10S438/933; Y10S438/938
Claims Analysis
Total Claims: 64
Claim 1
Independent Claim
99 words
A single crystal heterostructure comprising: a substrate of a first semiconductor material having a crystalline structure and a first bulk lattice constant; an upper layer of a second epitaxially grown semiconductor material which is unstrained having a second bulk lattice constant different from said first bulk lattice constant; and an intermediate layer of a third epitaxially grown semiconductor material sandwiched between said substrate and said upper layer of a second semiconductor material having a partial strain therein due to its growth on said substrate and a partially relaxed in-plane lattice constant substantially equal to the second bulk lattice constant.
Claim 2
Dependent Claim
99 words
A single crystal heterostructure comprising: a substrate of a first semiconductor material having a crystalline structure and a first bulk lattice constant; an upper layer of a second epitaxially grown semiconductor material which is unstrained having a second bulk lattice constant different from said first bulk lattice constant; and an intermediate layer of a third epitaxially grown semiconductor material sandwiched between said substrate and said upper layer of a second semiconductor material having a partial strain therein due to its growth on said substrate and a partially relaxed in-plane lattice constant substantially equal to the second bulk lattice constant.
Claim 3
Dependent Claim
53 words
The heterostructure of claim 1 wherein the intermediate layer of a third semiconductor material has a bulk lattice constant sufficiently different from the bulk lattice constant of the first semiconductor material such that a percentage mismatch between said first semiconductor material and said intermediate layer of third semiconductor material is at least 2.5%.
Claim 4
Dependent Claim
35 words
The heterostructure of claim 1 wherein the strain of the third semiconductor material is partially relieved substantially by a planar array of edge type dislocations at the interface between the first and third semiconductor materials.
Claim 5
Dependent Claim
12 words
The heterostructure of claim 1 wherein the first semiconductor material is GaAs.
Claim 6
Dependent Claim
21 words
The heterostructure of claim 4 wherein the intermediate layer of third semiconductor material is In 0 .9 Ga 0 .1 As.
Claim 7
Dependent Claim
16 words
The heterostructure of claim 5 wherein the partially relaxed in-plane lattice constant is about 80% relaxed.
Claim 8
Dependent Claim
21 words
The heterostructure of claim 5 wherein the upper layer of second semiconductor material is In 0 .72 Ga 0 .28 As.
Claim 9
Dependent Claim
12 words
The heterostructure of claim 4 wherein GaAs has a (100) crystallographic configuration.
Claim 10
Dependent Claim
18 words
The heterostructure of claim 5 wherein the intermediate layer of third semiconductor material is between 3-10 nm thick.
Claim 11
Dependent Claim
22 words
The heterostructure of claim 4 wherein the layer of a third semiconductor material is GaInAs and the second semiconductor material is AlInAs.
Claim 12
Dependent Claim
22 words
The heterostructure of claim 4 wherein the layer of a third semiconductor material is AlInAs and the second semiconductor material is GaInAs.
Claim 13
Dependent Claim
36 words
The heterostructure of claim 4 wherein the second and third semiconductor materials are comprised of AlInAs, with the In concentration in the third semiconductor material being greater than the In concentration in the second semiconductor material.
Claim 14
Dependent Claim
36 words
The heterostructure of claim 4 wherein the second and third semiconductor materials are comprised of GaInAs, with the In concentration in the third semiconductor material being greater than the In concentration in the second semiconductor material.
Claim 15
Dependent Claim
19 words
The heterostructure of claim 4 wherein the second semiconductor material is InGaAs and the third semiconductor material is InAs.
Claim 16
Dependent Claim
18 words
The heterostructure of claim 14 wherein the second semiconductor material is In 0 .8 Ga 0 .2 As.
Claim 17
Dependent Claim
35 words
The heterostructure of claim 1 wherein the thickness of the intermediate layer of third semiconductor material is less than the thickness at which the partial strain is further relieved by 60 degree type threading dislocations.
Claim 18
Dependent Claim
24 words
The heterostructure of claim 2 wherein the percentage mismatch between said first semiconductor material and said third semiconductor material is between 3 and 7.5%.
Claim 19
Dependent Claim
12 words
The heterostructure of claim 1 wherein the first semiconductor material is Si.
Claim 20
Dependent Claim
12 words
The heterostructure of claim 18 wherein the third semiconductor material is GaInAs.
Claim 21
Dependent Claim
12 words
The heterostructure of claim 19 wherein the second semiconductor material is GaAs.
Claim 22
Dependent Claim
12 words
The heterostructure of claim 19 wherein the second semiconductor material is GaAlAs.
Claim 23
Dependent Claim
14 words
The heterostructure of claim 19 wherein the GaInAs material is comprised of 15-20% In.
Claim 24
Dependent Claim
70 words
The heterostructure of claim 1 further including a second intermediate layer of a fourth semiconductor material sandwiched between said upper layer of second semiconductor material and said intermediate layer of third semiconductor material, said second intermediate layer of fourth semiconductor material having a partial strain therein due to its growth on said third semiconductor material and a partially relaxed in-plane lattice constant substantially equal to the second bulk lattice constant.
Claim 25
Dependent Claim
57 words
The heterostructure of claim 23 wherein the second intermediate layer of fourth semiconductor material comprises In 0 .63 Ga 0 .37 As, said intermediate layer of third semiconductor material comprises In 0 .9 Ga 0 .1 As, said upper layer of second semiconductor material comprises In 0 .72 Ga 0 .28 As and said substrate comprises GaAs.
Claim 26
Dependent Claim
32 words
The heterostructure of claim 24 wherein the intermediate layer of third semiconductor material is about 10 nm thick and the second intermediate layer of fourth semiconductor material is about 20 nm thick.
Claim 27
Independent Claim
105 words
A method of providing a strain free semiconductor layer comprising the steps of: providing a substrate of a first semiconductor material having a crystalline structure and a first bulk lattice constant; epitaxially growing an intermediate layer of a second semiconductor material on said substrate having a second bulk lattice constant different from said first bulk lattice constant and having a partial strain therein due to its growth on said substrate and a partially relaxed in-plane lattice constant; and epitaxially growing an upper layer of a third semiconductor material which is unstrained having a lattice constant substantially equal to said partially relaxed in-plane strain lattice constant.
Claim 28
Independent Claim
105 words
A method of providing a strain free semiconductor layer comprising the steps of: providing a substrate of a first semiconductor material having a crystalline structure and a first bulk lattice constant; epitaxially growing an intermediate layer of a second semiconductor material on said substrate having a second bulk lattice constant different from said first bulk lattice constant and having a partial strain therein due to its growth on said substrate and a partially relaxed in-plane lattice constant; and epitaxially growing an upper layer of a third semiconductor material which is unstrained having a lattice constant substantially equal to said partially relaxed in-plane strain lattice constant.
Claim 29
Dependent Claim
39 words
The method of claim 26 wherein the intermediate layer has a bulk lattice constant sufficiently different from the bulk lattice constant of the substrate such that a percentage mismatch between said substrate and intermediate layer is at least 2.5%.
Claim 30
Dependent Claim
35 words
The method of claim 26 wherein the strain of the intermediate layer is partially relieved substantially by a planar array of edge type dislocations at the interface between said substrate layer and said intermediate layer.
Claim 31
Dependent Claim
10 words
The method of claim 26 wherein the substrate comprises GaAs.
Claim 32
Dependent Claim
11 words
The method of claim 29 wherein the intermediate layer comprises InAs.
Claim 33
Dependent Claim
16 words
The method of claim 30 wherein the partially relaxed in-plane lattice constant is about 80% relaxed.
Claim 34
Dependent Claim
16 words
The method of claim 30 wherein the thickness of the intermediate layer is between 3-10 nm.
Claim 35
Dependent Claim
11 words
The method of claim 30 wherein the upper layer comprises InGaAs.
Claim 36
Dependent Claim
15 words
The method of claim 29 wherein the intermediate layer comprises one of GaInAs and AlInAs.
Claim 37
Dependent Claim
34 words
The method of claim 34 where the upper layer comprises one of GaInAs and AlInAs, and wherein the In concentration in the intermediate layer is greater than the In concentration in the upper layer.
Claim 38
Dependent Claim
10 words
The method of claim 26 wherein the substrate comprises Si.
Claim 39
Dependent Claim
11 words
The method of claim 36 wherein the intermediate layer comprises GaInAs.
Claim 40
Dependent Claim
15 words
The method of claim 37 wherein the upper layer comprises one of GaAs and GaAlAs.
Claim 41
Dependent Claim
12 words
The method of claim 37 wherein the intermediate layer comprises 15-20% In.
Claim 42
Dependent Claim
14 words
The method of claim 29 wherein the GaAs substrate has a (100) crystallographic configuration.
Claim 43
Dependent Claim
29 words
The method of claim 35 wherein the intermediate layer comprises In 0 .9 Ga 0 .1 As and the upper layer comprises In 0 .72 Ga 0 .28 As.
Claim 44
Dependent Claim
53 words
The method of claim 30 further including the step of epitaxially growing a second intermediate layer of a fourth semiconductor material on said intermediate layer of a second semiconductor material having a partial strain therein due to its growth on said layer of second semiconductor material and a partially relaxed in-plane lattice constant.
Claim 45
Dependent Claim
49 words
The method of claim 42 wherein the first semiconductor material comprises GaAs, the second semiconductor material comprises In 0 .9 Ga 0 .1 As, the third semiconductor material comprises In 0 .72 Ga 0 .28 As and the fourth semiconductor material comprises In 0 .63 Ga 0 .28 As.
Claim 46
Independent Claim
70 words
A method for providing a strain free semiconductor layer comprising the steps of: epitaxially growing an intermediate layer of a first semiconductor material on a substrate of a second semiconductor material; interrupting the growing of said intermediate layer at a point wherein the strain lattice constant is partially relaxed; and epitaxially growing an upper layer of a third semiconductor material on said intermediate layer which is unstrained and defect free.
Claim 47
Independent Claim
70 words
A method for providing a strain free semiconductor layer comprising the steps of: epitaxially growing an intermediate layer of a first semiconductor material on a substrate of a second semiconductor material; interrupting the growing of said intermediate layer at a point wherein the strain lattice constant is partially relaxed; and epitaxially growing an upper layer of a third semiconductor material on said intermediate layer which is unstrained and defect free.
Claim 48
Dependent Claim
24 words
The method of claim 44 wherein the substrate and intermediate layers have mismatched bulk lattice constants wherein the percentage mismatch is at least 2.5%.
Claim 49
Dependent Claim
28 words
The method of claim 45 wherein the bulk lattice constant of the upper layer is substantially equal to said partially relieved strain lattice constant of the intermediate layer.
Claim 50
Dependent Claim
10 words
The method of claim 44 wherein the substrate comprises GaAs.
Claim 51
Dependent Claim
11 words
The method of claim 47 wherein the intermediate layer comprises InAs.
Claim 52
Dependent Claim
16 words
The method of claim 48 wherein the partially relieved strain lattice constant is about 80% relieved.
Claim 53
Dependent Claim
16 words
The method of claim 48 wherein the thickness of the intermediate layer is between 3-10 nm.
Claim 54
Dependent Claim
11 words
The method of claim 48 wherein the upper layer comprises InGaAs.
Claim 55
Dependent Claim
16 words
The method of claim 47 wherein the intermediate layer comprises one of InAs, GaInAs and AlInAs.
Claim 56
Dependent Claim
31 words
The method of claim 52 wherein the upper layer comprises one of GaInAs and AlInAs and wherein the In concentration is greater in the intermediate layer than in the upper layer.
Claim 57
Dependent Claim
10 words
The method of claim 44 wherein the substrate comprises Si.
Claim 58
Dependent Claim
11 words
The method of claim 54 wherein the intermediate layer comprises GaInAs.
Claim 59
Dependent Claim
15 words
The method of claim 55 wherein the upper layer comprises one of GaAs and GaAlAs.
Claim 60
Dependent Claim
12 words
The method of claim 56 wherein the intermediate layer comprises 15-20% In.
Claim 61
Dependent Claim
14 words
The method of claim 47 wherein the GaAs substrate has a (100) crystallographic configuration.
Claim 62
Dependent Claim
29 words
The method of claim 53 wherein the intermediate layer comprises In 0 .9 Ga 0 .1 As and the upper layer comprises In 0 .72 Ga 0 .28 As.
Claim 63
Dependent Claim
53 words
The method of claim 41 further including the step of epitaxially growing a second intermediate layer of a fourth semiconductor material on said intermediate layer of a second semiconductor material having a partial strain therein due to its growth on said layer of second semiconductor material and a partially relaxed in-plane lattice constant.
Claim 64
Dependent Claim
49 words
The method of claim 60 wherein the first semiconductor material comprises GaAs, the second semiconductor material comprises In 0 .9 Ga 0 .1 As, the third semiconductor material comprises In 0 .72 Ga 0 .28 As and the fourth semiconductor material comprises In 0 .63 Ga 0 .28 As.
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