US3751310A
Expired / Lapsed
US
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Germanium doped epitaxial films by the molecular beam method
Assignee: AT&T Inc
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Filing: 1971-03-25
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Granted: 1973-08-07
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Expires: 1991-03-25
Abstract
Abstract Single crystal thin films of Group III(a)-V(a) compounds grown by the molecular beam epitaxy method are doped during growth with germanium. Generally, the Group IV dopants such as tin and silicon produce n-type crystals. However, germanium produces either n-type or p-type crystals depending on whether the growth surface structure is stabilized in the Group V(a) element or the Group III(a) elements, respectively, which in turn depends on both the substrate temperature and the ratio of the Group V(a) element to Group III(a) elements in the molecular beam.
Inventors
- 👤 A Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:51
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B29/00; C30B29/10; C30B29/40; H; H10; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H10P; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H10P14/3438; H10P14/3441; H10P14/3442; H10P14/3444; Y; Y10; Y10S; Y10S148/00; Y10S148/002; Y10S148/018; Y10S148/02; Y10S148/065; Y10S148/072; Y10S148/169; Y10S252/00; Y10S252/95; Y10S252/951; Y10S438/00; Y10S438/914; Y10S438/915; Y10S438/925
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
48 words
The method of claim 1 wherein the material of said thin film is selected from the group consisting of GaxAl1 xAs, 0 < or = x < or = 1, and GaP and said substrate surface is preheated to a temperature in the range of about 450*-650* Centigrade.
Claim 2
Dependent Claim
28 words
The method of claim 2 wherein said material comprises GaxAl1 xAs , 0 < or = x < or = 1, and said substrate comprises single crystal GaAs.
Claim 3
Dependent Claim
44 words
The method of claim 3 wherein said surface is stabilized with respect to As to produce a thin film of n-GaxAl1 xAs and is stabilized with respect to Gax and Al1 x when it is desired to produce a thin film of p-GaxAl1 xAs.
Claim 4
Independent Claim
290 words
A method for the successive epitaxial growth upon a semiconductor surface of at least two thin films of different conductivity type of a material having a composition A1 xBxC where 0 < or = x < or = 1, A is a first Group III(a) element, B is a second Group III(a) element and C is a Group V(a) element, said Group III and Group V elements being selected from the group consisting of aluminum, gallium and indium, and phosphorus, arsenic and antimony, respectively, comprising the steps of reducing the background pressure to a subatmospheric pressure, directing at least one molecular beam comprising a dopant, at least one Group III(a) element and a Group V(a) element upon said substrate surface for a time period sufficient to effect growth of said thin films each of a desired thickness, said substrate surface being preheated to a temperature effective to allow atoms impinging thereon to migrate to surface sites to form said epitaxial film and effective to produce congruent evaporation of said at least one Group III(a) element and said Group V(a) element therefrom, and characterized in that: said dopant comprises Ge, the temperature of said substrate and the ratio of said Group V(a) element to said at least one Group III(a) element in said at least one beam are mutually adapted to produce on said surface a molecular structure stabilized with respect to said Group V(a) element when it is desired that germanium incorporate into one of said thin films as an n-type dopant, and adapted to produce on said surface a molecular structure stabilized with respect to said at least one Group III(a) element when it is desired that germanium incorporate into another of said thin films as a p-type dopant.
Claim 5
Dependent Claim
35 words
The method of claim 5 wherein said material comprises Ga1 xAlxAs, 0 < or = x < or = 1, and said substrate is preheateD to a temperature in the range of about 450*-650* Centigrade.
Claim 6
Dependent Claim
12 words
The method of claim 6 wherein said substrate comprises single crystal GaAs.
Claim 7
Dependent Claim
30 words
The method of claim 5 including the step of controlling the arrival rate of said Group III(a) elements so that said at least two thin films have different band gaps.
Claim 8
Dependent Claim
36 words
The method of claim 8 wherein said material comprises Ga1 xAlxAs, 0 < or = x < or = 1, and said substrate is preheated to a temperature within the range of about 450*-650* degrees Centigrade.
Claim 9
Dependent Claim
48 words
The method of claim 9 for growing on a single crystal GaAs substrate successive thin films comprising growing an n-type layer of Ga1 xAlxAs, 0<x< 1, growing a p-type layer of Ga1 yAlyAs, 0 < or = y<1, y<x, and growing a p-type layer of Ga1 zAlzAs, 0<z<1,z>y.
Claim 10
Dependent Claim
49 words
The method of claim 9 for growing on a single crystal GaAs substrate successive thin films comprising growing a p-type layer of Ga1 xAlxAs, 0<x<1, growing an n-type layer of Ga1 yAlhd yAs, 0 < or = y<1, y<x, and growing an n-type layer of Ga1 zAlzAs, 0<z<1, z>y.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |