US4270997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser photochemical synthesis of Si3 N4
Assignee: United States Department of the Army
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Filing: 1980-04-07
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Granted: 1981-06-02
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Expires: 2000-04-07
Abstract
Abstract Disclosed is a method to synthesize Si 3 N 4 from SiX 4 +NX.s3, wherein X is selected from hydrogen and/or fluorine, by laser photochemical reaction (LPR) technique in a controlled atmosphere chamber wherein the reactant gases are maintained at pressures between about 10 and about 200 torr in a molar volume ratio of about 3 of the SiX 4 to about 4 of the NX 3 . The LPR method produces the compound Si 3 N 4 at room temperature while employing a pulsed laser or a continuous wave laser.
Inventors
- 👤 James A. Merritt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:26
CPC Classifications
C; C03; C03C; C03C25/00; C03C25/10; C03C25/42; C01; C01B; C01B21/00; C01B21/06; C01B21/068; C03C25/12; C03C25/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
147 words
A method of producing Si 3 N 4 by laser photochemical reaction initiated by irradiating the reactant gases in a controlled atmosphere laser reaction chamber, said method comprising: (a) introducing into a laser reaction chamber that is provided with a salt window transparent to laser radiation, a controlled atmosphere of the reactant gases of SiX 4 and NX 3 , wherein X is selected from hydrogen and fluorine, said gases maintained in a controlled atmosphere at pressures between about 10 and about 200 torr in a molar volume ratio of about 3 of said SiX 4 to about 4 of said NX 3 ; (b) irradiating said controlled atmosphere with the P(36) line of a CO 2 laser to produce said Si 3 N 4 as a powdery solid; and, (c) separating and removing said powdery solid of Si 3 N 4 from said laser reaction chamber.
Claim 2
Independent Claim
147 words
A method of producing Si 3 N 4 by laser photochemical reaction initiated by irradiating the reactant gases in a controlled atmosphere laser reaction chamber, said method comprising: (a) introducing into a laser reaction chamber that is provided with a salt window transparent to laser radiation, a controlled atmosphere of the reactant gases of SiX 4 and NX 3 , wherein X is selected from hydrogen and fluorine, said gases maintained in a controlled atmosphere at pressures between about 10 and about 200 torr in a molar volume ratio of about 3 of said SiX 4 to about 4 of said NX 3 ; (b) irradiating said controlled atmosphere with the P(36) line of a CO 2 laser to produce said Si 3 N 4 as a powdery solid; and, (c) separating and removing said powdery solid of Si 3 N 4 from said laser reaction chamber.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-01 | 1984-12-01 | 1985-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-01 | 1988-12-01 | 1989-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-01 | 1992-12-01 | 1993-06-02 | $7700.00 | Window Closed / Lapsed |