US5288527A
Expired / Lapsed
US
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Silicon nitride thin films with improved properties
Assignee: Saint Gobain Glass France SAS
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Filing: 1991-11-21
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Granted: 1994-02-22
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Expires: 2011-11-21
Abstract
Abstract A method for preparing silicon nitride films with improved properties and characterized by a limited concentration of hydrogen atoms, a high index of refraction, resistance to attack by a hydrofluoric solution, prevention of diffusion of alkalines and oxygen, and good dielectric properties such as optical gap. The process of preparation uses plasma CVD with ammonia. The invention can be applicable to flat screens, TFT transistors and functional glazings.
Inventors
- 👤 Didier Jousse
- 👤 Pablo Vilato
- 👤 Jean-Claude Bruyere
- 👤 Brigette Reynes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:36
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/34; C23C16/345; C03; C03C; C03C17/00; C03C17/22; C03C17/225; C03C2217/00; C03C2217/20; C03C2217/28; C03C2217/281; C03C2218/00; C03C2218/10; C03C2218/15; C03C2218/152; C03C2218/153
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
85 words
A process for the production of a silicon nitride film by a chemical vapor deposition, comprising the steps of: generating a plasma from a gas mixture of SiH 4 and N 2 in helium in the presence of an alternating field having a frequency less than 1 MHz; and introducing NH 3 into the plasma, so that a ratio R is greater than 0.95 and less than 1.00, where R is defined as, ##EQU2## wherein the plasma yields on a substrate the silicon nitride film.
Claim 2
Dependent Claim
85 words
A process for the production of a silicon nitride film by a chemical vapor deposition, comprising the steps of: generating a plasma from a gas mixture of SiH 4 and N 2 in helium in the presence of an alternating field having a frequency less than 1 MHz; and introducing NH 3 into the plasma, so that a ratio R is greater than 0.95 and less than 1.00, where R is defined as, ##EQU2## wherein the plasma yields on a substrate the silicon nitride film.
Claim 3
Dependent Claim
27 words
The process according to claim 1, wherein the silicon nitride film has an index of refraction greater than 1.97, and wherein R is between 0.97 and 0.99.
Claim 4
Dependent Claim
27 words
The process according to claim 1, wherein the silicon nitride film has an optical gap greater than 5 eV, and wherein R is between 0.95 and 0.97.
Claim 5
Dependent Claim
25 words
The process according to claim 1, wherein the temperature of the substrate onto which the silicon nitride film is deposited is less than 400° C.
Claim 6
Dependent Claim
19 words
The process according to claim 1, wherein a proportion of SiH 4 relative to helium is less than 5%.
Claim 7
Dependent Claim
19 words
The process according to claim 1, wherein the frequency of the alternating field is between 10 and 400 kHz.
Claim 8
Dependent Claim
16 words
The process according to claim 6, wherein the frequency of the alternating field is 50 kHz.
Claim 9
Dependent Claim
45 words
The process according to claim 1, further comprising: fabricating a flat screen incorporating the silicon nitride film, including engraving transistors on the flat screen, wherein glass in the flat screen is protected from attack by the silicon nitride film during the engraving of said transistors.
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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) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |