Patent US4028151A successfully refreshed from Google Patents.
US4028151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of impregnating a semiconductor with a diffusant and article so formed
Assignee: BP Solar International LLC
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Filing: 1976-01-19
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Granted: 1977-06-07
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Expires: 1996-01-19
Abstract
Abstract Crystalline silicon wafers have an electrical junction formed at a surface thereof by impregnating the surface with a diffusant, such as phosphorus, in an atmosphere that includes significant quantities of helium.
Inventors
- 👤 Joseph Lindmayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:30
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/12; H10F; H10F71/00; H10F71/121; H10P32/17; H10P32/171; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547; Y02P; Y02P70/00; Y02P70/50; Y10; Y10S; Y10S148/00; Y10S148/024; Y10S148/153; Y10S438/00; Y10S438/909
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
72 words
A method of forming a junction at a surface of a silicon wafer, comprising heating said surface with a diffusant in the presence of an inert gas selected from the group consisting of helium and neon in an amount sufficient to enhance the electrical performance of the junction resulting from penetration of said wafer surface by said diffusant compared to a junction formed by diffusion in an atmosphere of argon or nitrogen.
Claim 2
Independent Claim
72 words
A method of forming a junction at a surface of a silicon wafer, comprising heating said surface with a diffusant in the presence of an inert gas selected from the group consisting of helium and neon in an amount sufficient to enhance the electrical performance of the junction resulting from penetration of said wafer surface by said diffusant compared to a junction formed by diffusion in an atmosphere of argon or nitrogen.
Claim 3
Dependent Claim
17 words
A silicon wafer having a surface impregnated with diffusant by performance of the method of claim 1.
Claim 4
Dependent Claim
25 words
A method of forming a junction at the surface of a silicon wafer as claimed in claim 1, in which the inert gas is helium.
Claim 5
Dependent Claim
24 words
A method of forming a junction at the surface of a silicon wafer as claimed in claim 1, in which the diffusant is phosphorus.
Claim 6
Dependent Claim
30 words
A method of forming a junction at the surface of a silicon wafer as claimed in claim 1, in which the inert gas is helium and the diffusant is phosphorus.
Claim 7
Independent Claim
96 words
A method of forming a junction at a surface of a silicon wafer, comprising positioning the wafer in a furnace, introducing into the furnace a diffusant in gaseous form, maintaining in said furnace an atmosphere including in addition to said diffusant helium gas in an amount sufficient to enhance the electrical performance of the junction subsequently formed in comparison to a junction formed by diffusion in a similar atmosphere of argon or nitrogen, and heating the contents of the furnace for a period of time sufficient to effect penetration of the wafer surface by the diffusant.
Claim 8
Independent Claim
96 words
A method of forming a junction at a surface of a silicon wafer, comprising positioning the wafer in a furnace, introducing into the furnace a diffusant in gaseous form, maintaining in said furnace an atmosphere including in addition to said diffusant helium gas in an amount sufficient to enhance the electrical performance of the junction subsequently formed in comparison to a junction formed by diffusion in a similar atmosphere of argon or nitrogen, and heating the contents of the furnace for a period of time sufficient to effect penetration of the wafer surface by the diffusant.
Claim 9
Dependent Claim
31 words
A method of forming a junction at a surface of a silicon wafer as claimed in claim 6, in which said diffusant is phosphorus and the gaseous form thereof is phosphine.
Claim 10
Dependent Claim
25 words
A method of forming a junction at a surface of a silicon wafer as claimed in claim 6, in which said atmosphere also contains oxygen.
Claim 11
Dependent Claim
36 words
A method of forming a junction at a surface of a silicon wafer as claimed in claim 6, in which there is a continuous introduction into the furnace of phosphine in a dilutant, oxygen and helium.
Claim 12
Dependent Claim
34 words
A method of forming a junction at a surface of a silicon wafer as claimed in claim 9, in which the atmosphere in the oven is composed of greater than 10% helium by volume.
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) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |