Patent US1473157A successfully refreshed from Google Patents.
Patent US5200028A successfully refreshed from Google Patents.
US5200028A
Expired / Lapsed
US
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Etching process of silicon material
Assignee: Sony Corp
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Filing: 1991-08-07
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Granted: 1993-04-06
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Expires: 2011-08-07
Abstract
Abstract A process is disclosed for etching a silicon-based structure comprised of a silicon layer and a high-melting silicide layer. Good shaping results from etching of the two layers with use of two gaseous mixtures having their respective different ratios of a hydrogen bromide gas and a fluorine radical-donating gas. Separate etching is possible of the silicon layer with a hydrogen bromide gas and of the silicide layer with a gaseous mixture of the above type. A silicon-containing layer is also etched with a hydrogen gas alone with the end point of etching being precisely detected.
Inventors
- 👤 Tetsuya Tatsumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:09
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
87 words
A process for subjecting a silicon-based structure to etching, said structure having a silicon layer and a high-melting silicide layer superposed one on the other over a substrate, which process comprises etching said silicon layer with a first gaseous medium, and etching said silicide layer with a second gaseous medium, each of said first and second gaseous media having a hydrogen bromide gas and a fluorine radical-donating gas contained in a selected ratio, said first and second gaseous media differing in each selected ratios from each other.
Claim 2
Dependent Claim
87 words
A process for subjecting a silicon-based structure to etching, said structure having a silicon layer and a high-melting silicide layer superposed one on the other over a substrate, which process comprises etching said silicon layer with a first gaseous medium, and etching said silicide layer with a second gaseous medium, each of said first and second gaseous media having a hydrogen bromide gas and a fluorine radical-donating gas contained in a selected ratio, said first and second gaseous media differing in each selected ratios from each other.
Claim 3
Dependent Claim
17 words
A process according to claim 1, wherein said silicide layer comprises a tungsten, titanium or molybdenum metal.
Claim 4
Dependent Claim
106 words
A process for subjecting a silicon-based structure to etching, said structure having a silicon layer and a high-melting silicide layer superposed one on the other over a substrate, which process comprises etching said silicon layer with a first gaseous medium, and etching said silicide layer with a second gaseous medium, each of said first and second gaseous media having a hydrogen bromide gas and a fluorine radical-donating gas contained in a selected ratio, said first and second gaseous media differing in each selected ratios from each other, and wherein said fluorine radical-donating gas is a sulfur hexafluoride, nitrogen trifluoride, chlorine trifluoride, fluorine or hydrogen fluoride gas.
Claim 5
Dependent Claim
106 words
A process for subjecting a silicon-based structure to etching, said structure having a silicon layer and a high-melting silicide layer superposed one on the other over a substrate, which process comprises etching said silicon layer with a first gaseous medium, and etching said silicide layer with a second gaseous medium, each of said first and second gaseous media having a hydrogen bromide gas and a fluorine radical-donating gas contained in a selected ratio, said first and second gaseous media differing in each selected ratios from each other, and wherein said fluorine radical-donating gas is a sulfur hexafluoride, nitrogen trifluoride, chlorine trifluoride, fluorine or hydrogen fluoride gas.
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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) | 1996-04-05 | 1996-10-05 | 1997-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-05 | 2000-10-05 | 2001-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-05 | 2004-10-05 | 2005-04-06 | $7700.00 | Window Closed / Lapsed |