Patent US4430138A successfully refreshed from Google Patents.
US4430138A
Expired / Lapsed
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Microwave plasma etching apparatus having fan-shaped discharge
Assignee: Hitachi Ltd
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Filing: 1980-04-07
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Granted: 1984-02-07
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Expires: 2000-04-07
Abstract
Abstract In a microwave plasma etching apparatus wherein the surface of a sample is exposed to a plasma generated by microwave discharge, thereby to subject the sample surface to an etching processing; the sample is transported while revolving along a circular orbit in a plasma exposure region, and the section of the plasma exposure region is put into the shape of a fan whose pivot coincides with the central point of the circuit orbit, whereby the enhancement of the etching processing capability and the uniformity of the etching speed are achieved.
Inventors
- 👤 Keizo Suzuki
- 👤 Sadayuki Okudaira
- 👤 Shigeru Nishimatsu
- 👤 Ichiro Kanomata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:49
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0418; H10P72/0421; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32192; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/30; H01J2237/00; H01J2237/32; H01J2237/33; H01J2237/334; H01J2237/3343
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
A microwave plasma etching apparatus for exposing a sample to a microwave discharge plasma, comprising: a discharge tube which has an opening portion confronting the surface of said sample, said opening portion being formed into the shape of a fan; means to generate a microwave discharge plasma in said discharge tube; and means for moving said sample along a circular path whose center coincides with the pivot of said fan, wherein said discharge tube is gradually tapered from a portion having a circular sectional shape towards said fan-shaped opening portion.
Claim 2
Dependent Claim
90 words
A microwave plasma etching apparatus for exposing a sample to a microwave discharge plasma, comprising: a discharge tube which has an opening portion confronting the surface of said sample, said opening portion being formed into the shape of a fan; means to generate a microwave discharge plasma in said discharge tube; and means for moving said sample along a circular path whose center coincides with the pivot of said fan, wherein said discharge tube is gradually tapered from a portion having a circular sectional shape towards said fan-shaped opening portion.
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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) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |