US3931056A
Expired / Lapsed
US
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Solid diffusion sources for phosphorus doping containing silicon and zirconium pyrophosphates
Assignee: Unifrax I LLC
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Filing: 1974-08-26
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Granted: 1976-01-06
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Expires: 1994-08-26
Abstract
Abstract Solid diffusion sources for phosphorus doping comprise from 5 to 95 percent SiP 2 O 7 with an inert phase of ZrP 2 O 7 . While such materials may be hot-pressed, it is preferred to cold-press and sinter to obtain diffusion source wafers of the appropriate dimensions and porosity. A preferred composition comprises from 25 to 75 weight percent SiP 2 O 7 the balance ZrP 2 O 7 . Fabrication parameters range from about 4000 psi to about 20,000 psi pressure during cold-pressing, and from about 1080°C to about 1190°C firing temperature.
Inventors
- 👤 Thomas A. Myles
- 👤 Curtis E. Zimmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:00
CPC Classifications
C; C30; C30B; C30B31/00; C30B31/06; C30B31/16; C30B31/165; C04; C04B; C04B35/00; C04B35/01; C04B35/447; C04B35/622; C04B35/64; C04B35/645; H; H10; H10P; H10P32/00; H10P32/10; H10P32/12; H10P32/17; H10P32/171; H10P32/19
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
40 words
A solid phosphorus containing source body for semiconductor diffusion doping, said body consisting essentially of from about 5 to about 95 percent by weight of silicon pyrophosphate and from about 95 to about 5 percent by weight of zirconium pyrophosphate.
Claim 2
Dependent Claim
40 words
A solid phosphorus containing source body for semiconductor diffusion doping, said body consisting essentially of from about 5 to about 95 percent by weight of silicon pyrophosphate and from about 95 to about 5 percent by weight of zirconium pyrophosphate.
Claim 3
Dependent Claim
36 words
A solid phosphorus body as set forth in claim 1 consisting essentially of from about 25 to about 75 percent by weight silicon pyrophosphate and from about 25 to about 75 percent by weight zirconium pyrophosphate.
Claim 4
Independent Claim
66 words
A method for the formation of solid phosphorus diffusion bodies comprising preparing a blend consisting essentially of from 5 to 95 weight percent SiP 2 O 7 with from 95 to 5 weight percent ZrP 2 O 7 , cold-pressing a portion of said blend to thereby form a shaped unfired body, and sintering said body at a temperature of from about 1080°C to about 1200°C.
Claim 5
Independent Claim
66 words
A method for the formation of solid phosphorus diffusion bodies comprising preparing a blend consisting essentially of from 5 to 95 weight percent SiP 2 O 7 with from 95 to 5 weight percent ZrP 2 O 7 , cold-pressing a portion of said blend to thereby form a shaped unfired body, and sintering said body at a temperature of from about 1080°C to about 1200°C.
Claim 6
Dependent Claim
25 words
A method as set forth in claim 3 wherein said cold-pressing is conducted at a pressure of from about 4,000 psi to about 20,000 psi.
Claim 7
Dependent Claim
26 words
A method as set forth in claim 4 wherein said blend consists essentially of SiP 2 O 7 and ZrP 2 O 7 in 1:1 proportions.
Claim 8
Dependent Claim
40 words
A method as set forth in claim 5 wherein said sintering is conducted at a temperature of from about 1090°C to about 1120°C, and said cold-pressing is conducted at a pressure of from about 10,000 psi to about 12,000 psi.
Claim 9
Independent Claim
108 words
A method for preparing phosphorus dopants comprising SiP 2 O 7 , said method comprising the steps of: a. forming a blend of from about 5 to about 95 weight percent SiP 2 O 7 , the balance ZrP 2 O 7 ; b. adding to said blend a volatilizable organic binder; c. pressing said blend containing said binder at a pressure of from 4,000 psi to 20,000 psi to form a wafer of the desired dimensions; and d. firing said wafer at an elevated temperature to volatilize said binder and form a porous wafer consisting essentially of SiP 2 O 7 and ZrP 2 O 7 .
Claim 10
Independent Claim
108 words
A method for preparing phosphorus dopants comprising SiP 2 O 7 , said method comprising the steps of: a. forming a blend of from about 5 to about 95 weight percent SiP 2 O 7 , the balance ZrP 2 O 7 ; b. adding to said blend a volatilizable organic binder; c. pressing said blend containing said binder at a pressure of from 4,000 psi to 20,000 psi to form a wafer of the desired dimensions; and d. firing said wafer at an elevated temperature to volatilize said binder and form a porous wafer consisting essentially of SiP 2 O 7 and ZrP 2 O 7 .
Claim 11
Dependent Claim
26 words
A method as set forth in claim 7 wherein said SiP 2 O 7 is essentially free of any Si 2 P 2 O 9 .
Claim 12
Dependent Claim
34 words
A method as set forth in claim 8 wherein said pressing is at a pressure of from about 10,000 psi to 12,000 psi and said firing temperature is from about 1080°C to about 1190°C.
Claim 13
Dependent Claim
33 words
A method as set forth in claim 9 wherein the initial blend consists of from 25 to 75 weight percent SiP 2 O 7 , the balance being ZrP 2 O 7 .
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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) | 1979-01-05 | 1979-07-07 | 1980-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-05 | 1983-07-07 | 1984-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-05 | 1987-07-07 | 1988-01-06 | $7700.00 | Window Closed / Lapsed |