Patent US3625749A successfully refreshed from Google Patents.
US3625749A
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Method for deposition of silicon dioxide films
Assignee: Panasonic Holdings Corp
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Filing: 1967-03-31
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Granted: 1971-12-07
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Expires: 1987-03-31
Abstract
Abstract An improved method for depositing silicon dioxide film on surfaces of substrates, which are stable at temperatures of 730* C. and above, by passing onto the surfaces thereof maintained at 730* C. or above, a gaseous hydrogen-carbon dioxide-silicon tetrafluoride mixture wherein the silicon tetrafluoride concentration is 0.005-0.1 percent by volume and the carbon dioxide concentration is 8 to 92 percent by volume. The film is useful for diffusion-masking films for selective diffusion in fabrication or for passivating films.
Inventors
- 👤 Satoshi Yoshioka
- 👤 Shigetoshi Takayanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:33
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/40; C23C16/401; C23C16/402
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
24 words
A method according to claim 1, wherein the semiconductor material is selected from the group consisting of silicon, germanium, gallium arsenide and gallium phosphide.
Claim 2
Dependent Claim
104 words
A method according to claim 1, wherein the gaseous mixture of hydrogen, carbon dioxide and silicon tetrafluoride is prepared by feeding hydrogen into an evaporator charged with silicon tetrafluoride and maintained at -135* C. to saturate the hydrogen with said fluoride, and then mixing the silicon tetrafluoride saturated hydrogen with hydrogen and carbon dioxide, wherein gas concentrations of the silicon tetrafluoride and the carbon dioxide are regulated to become 0.06 percent by volume and 40 percent by volume, respectively, and applYing the thus-prepared mixed gas onto the surfaces of said semiconductor substrate heated at 800* C. to deposit thereon a thin silicon dioxide film.
Claim 3
Dependent Claim
130 words
A method according to claim 1, wherein the gaseous mixture of hydrogen, carbon dioxide and silicon tetrafluoride is prepared by feeding hydrogen to a hydrogen fluoride evaporator maintained at -75* C. to contain hydrogen fluoride in an amount corresponding to 0.12 percent of reaction gas, passing the hydrogen fluoride and the hydrogen through a tube packed with silica fragments and heated to 150* C. to obtain a gas containing silicon tetrafluoride, mixing the thus-obtained gas with hydrogen and carbon dioxide to prepare a reaction gas having a silicon tetrafluoride concentration of 0.03 percent by volume and a carbon dioxide concentration of 20 percent by volume, and applying the mixed reaction gas onto the surfaces of said semiconductor substrate heated at 800* C. to deposit thereon a thin silicon dioxide film.
Claim 4
Dependent Claim
136 words
A method according to claim 1, wherein the gaseous mixture of hydrogen, carbon dioxide and silicon tetrafluoride is prepared by feeding hydrogen to a hydrogen fluoride evaporator maintained at -75* C. to form a mixed gas containing hydrogen fluoride in an amount corresponding to 0.12 percent by volume of reaction gas, passing the hydrogen fluoride and hydrogen gas through a tube packed with silica fragments and heated to 150* C. to obtain a gas containing silicon tetrafluoride, mixing the thus-formed gas with hydrogen and carbon dioxide to prepare a reaction gas having a silicon tetrafluoride concentration of 0.005 percent by volume and a carbon dioxide concentration of 8 percent by volume and applying the mixed reaction gas onto the surfaces of said semiconductor substrate heated to 800* C. to deposit thereon a thin silicon dioxide film.
References Cited (Backward Citations)
US2535036A
Cited
US3087787A
Cited
US3203759A
Cited
US3233969A
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US3273963A
Cited
US3306768A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |