US4025464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition for diffusing phosphorus
Assignee: Individual
•
Filing: 1975-05-13
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Granted: 1977-05-24
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Expires: 1995-05-13
Abstract
Abstract A phosphorus nitride-silicon oxide composition having good thermal stability and diffusion characteristics for use as a diffusant source of n-type impurities for a semi-conductor device.
Inventors
- 👤 Mitsuo Yamashita
- 👤 Akio Mikogami
- 👤 Masashi Hasegawa
- 👤 Hiroshi Oizumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:03
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/622; C04B35/64; C04B35/645; C30; C30B; C30B31/00; C30B31/06; C30B31/16; C30B31/165; H; H10; H10P; H10P32/00; H10P32/10; H10P32/19; Y; Y10; Y10S; Y10S252/00; Y10S252/95
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
60 words
A method for the preparation of a composition for diffusing phosphorus which comprises mixing 95- 30 parts by weight of phosphorus nitride powder with 5- 70 parts by weight of silicon dioxide powder and hot pressing the mixed powder at 700° - 950° C. under a pressure of 50- 500kg/cm 2 for 5- 60 minutes in an inert gas atmosphere.
Claim 2
Independent Claim
60 words
A method for the preparation of a composition for diffusing phosphorus which comprises mixing 95- 30 parts by weight of phosphorus nitride powder with 5- 70 parts by weight of silicon dioxide powder and hot pressing the mixed powder at 700° - 950° C. under a pressure of 50- 500kg/cm 2 for 5- 60 minutes in an inert gas atmosphere.
Claim 3
Dependent Claim
20 words
A method as claimed in claim 1 wherein white carbon prepared by a dry method is used as silicon dioxide.
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) | 1980-05-23 | 1980-11-22 | 1981-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-23 | 1984-11-22 | 1985-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-23 | 1988-11-22 | 1989-05-24 | $7700.00 | Window Closed / Lapsed |