US4719155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Epitaxial layer structure grown on graded substrate and method of growing the same
Assignee: NEC Corp
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Filing: 1985-10-17
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Granted: 1988-01-12
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Expires: 2005-10-17
Abstract
Abstract An intentional lattice mismatch, Δa/a where Δa is a difference in the lattice constant of a constant-composition layer and an epitaxial layer and a is the lattice constant of the constant-composition layer, is introduced into the epitaxial layer of a crystal structure having a graded composition layer sandwiched between a single crystal bulk substrate and the constant composition layer so as to alleviate strain resulting from a lattice constant variation in the graded substrate.
Inventors
- 👤 Takashi Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:51
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/32; H10P14/3242; H10P14/3244; H10P14/3254; H10D; H10D62/00; H10D62/80; H10D62/82; H10D62/824; H10F; H10F71/00; H10F71/127; H10F71/1272; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2909; H10P14/2911; H10P14/3202; H10P14/3214; H10P14/3218; H10P14/3221; H10P14/3248; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3418; H10P14/3421; H10P14/3424; H10P14/3428; H10P14/3431; H01; H01S; H01S5/00; H01S5/02; H01S5/0206; H01S5/0211; H01S5/0212; H01S5/30; H01S5/32; H01S5/3201; H01S5/323; H01S5/32308; H01S5/32325; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/544
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
133 words
A crystal structure comprising: a single crystal bulk substrate having a first lattice constant, a graded-composition layer formed on said bulk substrate, a constant-composition layer formed on said graded-composition layer, said graded-composition layer and said constant composition layer having a second lattice constant which is different from said first lattice constant, and an epitaxial layer grown on said constant-composition layer with an intentional lattice mismatch Δa/a therebetween (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer), the value of Δa/a being in the range of 1×10 -3 to 5×10 -3 so as to alleviate a strain stored in said graded-composition layer and constant-composition layer due to the difference of said first and second lattice constants.
Claim 2
Dependent Claim
133 words
A crystal structure comprising: a single crystal bulk substrate having a first lattice constant, a graded-composition layer formed on said bulk substrate, a constant-composition layer formed on said graded-composition layer, said graded-composition layer and said constant composition layer having a second lattice constant which is different from said first lattice constant, and an epitaxial layer grown on said constant-composition layer with an intentional lattice mismatch Δa/a therebetween (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer), the value of Δa/a being in the range of 1×10 -3 to 5×10 -3 so as to alleviate a strain stored in said graded-composition layer and constant-composition layer due to the difference of said first and second lattice constants.
Claim 3
Dependent Claim
25 words
A crystal structure as set forth in claim 1, wherein the epitaxial layer is selected from the group comprising GaAlAs, InGaAsP, and InGaAlAsP and ZnCdSSe.
Claim 4
Dependent Claim
17 words
A crystal structure as set forth in claim 1, wherein said crystal structure is a laser diode.
Claim 5
Dependent Claim
19 words
A crystal structure as set forth in claim 1 wherein Δa/a is from 3×10 -3 to 4×10 -3 .
Claim 6
Dependent Claim
148 words
A crystal structure comprising: a single crystal bulk substrate selected from the group consisting of GaAs, GaP and InP, a graded-composition layer formed on said bulk substrate, said graded-composition layer being selected from the group consisting of GaAsP and InAsP, a constant-composition layer formed on said graded-composition layer, said constant-composition layer being selected from the group consisting of GaAsP and InAsP, and an epitaxial layer grown on said constant-composition layer with an intentional lattice mismatch Δa/a therebetween (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer), the value of Δa/a being in the range of 1×10 -3 to 5×10 -3 so as to alleviate a strain stored in said graded-composition layer and constant-composition layer, said epitaxial layer being selected from the group consisting of GaAlAs, InGaAsP, InGaAlAsP, ZnCdSSe and InGaP.
Claim 7
Dependent Claim
148 words
A crystal structure comprising: a single crystal bulk substrate selected from the group consisting of GaAs, GaP and InP, a graded-composition layer formed on said bulk substrate, said graded-composition layer being selected from the group consisting of GaAsP and InAsP, a constant-composition layer formed on said graded-composition layer, said constant-composition layer being selected from the group consisting of GaAsP and InAsP, and an epitaxial layer grown on said constant-composition layer with an intentional lattice mismatch Δa/a therebetween (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer), the value of Δa/a being in the range of 1×10 -3 to 5×10 -3 so as to alleviate a strain stored in said graded-composition layer and constant-composition layer, said epitaxial layer being selected from the group consisting of GaAlAs, InGaAsP, InGaAlAsP, ZnCdSSe and InGaP.
Claim 8
Dependent Claim
120 words
A crystal structure comprising: a graded substrate having a graded-composition layer sandwiched between a single crystal bulk substrate and a constant-composition layer, said graded substrate inherently storing a strain due to a difference in the lattice constant between said single crystal bulk substrate and both of said graded-composition layer and constant-composition layer, and an epitaxial layer grown on said constant-composition layer with an intentional lattice mismatch Δa/a therebeween (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer), the value of Δa/a being in the range of 3×10 -3 to 5×10 -3 so as to alleviate said strain stored in said graded substrate.
Claim 9
Dependent Claim
120 words
A crystal structure comprising: a graded substrate having a graded-composition layer sandwiched between a single crystal bulk substrate and a constant-composition layer, said graded substrate inherently storing a strain due to a difference in the lattice constant between said single crystal bulk substrate and both of said graded-composition layer and constant-composition layer, and an epitaxial layer grown on said constant-composition layer with an intentional lattice mismatch Δa/a therebeween (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer), the value of Δa/a being in the range of 3×10 -3 to 5×10 -3 so as to alleviate said strain stored in said graded substrate.
Claim 10
Dependent Claim
154 words
In a crystal structure comprising an epitaxial layer grown on a graded substrate having a graded-composition layer sandwiched between a single crystal bulk substrate and a constant-composition layer, the improvement in that an intentional lattice mismatch Δa/a of about 1×10 -3 to 5×10 -3 (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer) is introduced into said epitaxial layer such that when the lattice constant in said graded-composition layer increases in the direction from said single crystal bulk substrate toward said constant-composition layer, the lattice constant of said epitaxial layer is larger than that of said constant-composition layer and when the lattice constant in said graded-composition layer decreases in the direction from said single crystal bulk substrate toward said constant-composition layer, the lattice constant of said epitaxial layer is smaller than that of said constant-composition layer.
Claim 11
Dependent Claim
154 words
In a crystal structure comprising an epitaxial layer grown on a graded substrate having a graded-composition layer sandwiched between a single crystal bulk substrate and a constant-composition layer, the improvement in that an intentional lattice mismatch Δa/a of about 1×10 -3 to 5×10 -3 (wherein Δa is a difference in the lattice constant between said constant-composition layer and said epitaxial layer, and a is the lattice constant of said constant-composition layer) is introduced into said epitaxial layer such that when the lattice constant in said graded-composition layer increases in the direction from said single crystal bulk substrate toward said constant-composition layer, the lattice constant of said epitaxial layer is larger than that of said constant-composition layer and when the lattice constant in said graded-composition layer decreases in the direction from said single crystal bulk substrate toward said constant-composition layer, the lattice constant of said epitaxial layer is smaller than that of said constant-composition layer.
References Cited (Backward Citations)
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