Patent US4029528A successfully refreshed from Google Patents.
US4029528A
Expired / Lapsed
US
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Method of selectively doping a semiconductor body
Assignee: RCA Corp
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Filing: 1976-08-30
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Granted: 1977-06-14
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Expires: 1996-08-30
Abstract
Abstract A method of selectively doping a semiconductor body with aluminum impurities comprises the step of forming a layer of silicon dioxide which is thick enough so that during the diffusion a masking portion of aluminum oxide is formed therein. The aluminum oxide formed serves as a mask against the penetration of aluminum impurities through the remaining silicon dioxide therebelow.
Inventors
- 👤 Wojciech Rosnowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:18
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/65; H10P14/6516; H10P14/6518; H10P32/00; H10P32/10; H10P32/12; H10P32/17; H10P32/171; H10P14/6322; H10P14/6546; H10P14/6938; H10P14/6939; H10P14/69391; Y; Y10; Y10S; Y10S148/00; Y10S148/033
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
A method of selectively doping a silicon body with aluminum impurities comprising the steps of: forming a layer of silicon dioxide on a surface of said body; selectively exposing portions of said surface through said layer; and subjecting said body to aluminum impurities at a temperature and for a time to form a pocket having a preselected surface impurity concentration and pre-drive in depth beneath said portions of said surface, said layer having a thickness such that said impurities are prevented from reaching said surface therebeneath.
Claim 2
Independent Claim
86 words
A method of selectively doping a silicon body with aluminum impurities comprising the steps of: forming a layer of silicon dioxide on a surface of said body; selectively exposing portions of said surface through said layer; and subjecting said body to aluminum impurities at a temperature and for a time to form a pocket having a preselected surface impurity concentration and pre-drive in depth beneath said portions of said surface, said layer having a thickness such that said impurities are prevented from reaching said surface therebeneath.
Claim 3
Dependent Claim
25 words
A method as claimed in claim 1 wherein: said layer forming step is carried out until said layer has a thickness of about 40,000 A.
Claim 4
Dependent Claim
54 words
A method as claimed in claim 1 wherein said layer forming step comprises the steps of: exposing said silicon body to an atmosphere of steam at a temperature of about 1200° C for about 17 hours; and cooling said body to a temperature of about 870° C at a rate of about 2° C/minute.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 1 wherein: said subjecting step is carried out at a temperature between about 1025° C to about 1175° C.
Claim 6
Dependent Claim
8 words
A method as claimed in claim 1 wherein:
Claim 7
Dependent Claim
14 words
said subjecting step is carried out at about 1150° C for about 3 hours.
Claim 8
Dependent Claim
14 words
said subjecting step is carried out at about 1150° C for about 3 hours.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-13 | 1980-12-13 | 1981-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-13 | 1984-12-13 | 1985-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-13 | 1988-12-13 | 1989-06-14 | $7700.00 | Window Closed / Lapsed |