US5472564A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of dry etching with hydrogen bromide or bromide
Assignee: Fujitsu Semiconductor Ltd
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Filing: 1993-08-11
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Granted: 1995-12-05
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Expires: 2013-08-11
Abstract
Abstract Plasma etching with hydrogen bromide or bromine as an etching gas allows a precise control in attaining vertical etching or taper etching with a desired taper angle by controlling the temperature of a mass to be etched, which mass is usually a semiconductor wafer.
Inventors
- 👤 Moritaka Nakamura
- 👤 Takashi Kurimoto
- 👤 Katsuhiko Iizuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:34
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01324; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/518; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
A process for selectively etching a mass, comprising: providing an etching mask over the mass to expose an area of the mass to be etched; and providing a plasma of an etching gas in contact with said mass in an etching chamber, whereby said exposed area of said mass is selectively etched, wherein said etching gas has a purity of 99.99% or more and contains as the main reactive component reacting with said mass hydrogen bromide, and wherein said etching chamber has no carbon-bearing material in contact with said plasma of the etching gas.
Claim 2
Dependent Claim
94 words
A process for selectively etching a mass, comprising: providing an etching mask over the mass to expose an area of the mass to be etched; and providing a plasma of an etching gas in contact with said mass in an etching chamber, whereby said exposed area of said mass is selectively etched, wherein said etching gas has a purity of 99.99% or more and contains as the main reactive component reacting with said mass hydrogen bromide, and wherein said etching chamber has no carbon-bearing material in contact with said plasma of the etching gas.
Claim 3
Dependent Claim
27 words
A process according to claim 1, wherein said etching gas contains less than 120 ppm of carbon content based on the total weight of said etching gas.
Claim 4
Dependent Claim
27 words
A process according to claim 2, wherein said etching gas contains less than 40 ppm of carbon content based on the total weight of said etching gas.
Claim 5
Dependent Claim
16 words
A process according to claim 2, wherein said etching mask is composed of a non-carbon-bearing material.
Claim 6
Dependent Claim
26 words
A process according to claim 1, wherein said mass is made of a polycrystalline silicon and said etching mask is made of silicon oxide or nitride.
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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) | 1998-12-04 | 1999-06-05 | 1999-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-04 | 2003-06-05 | 2003-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-04 | 2007-06-05 | 2007-12-05 | $7700.00 | Window Closed / Lapsed |