Patent US3971684A successfully refreshed from Google Patents.
US3971684A
Expired / Lapsed
US
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Etching thin film circuits and semiconductor chips
Assignee: HP Inc
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Filing: 1975-04-14
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Granted: 1976-07-27
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Expires: 1995-04-14
Abstract
Abstract A method is provided for etching thin film circuits or semiconductor chips to produce well defined vertically etched walls at rapid etching rates. The substrates to be etched are covered by masks and positioned on a cathode electrode enclosed in a container. Also enclosed in the container is a chemically-reactive gas used as an etchant. According to the method the cathode is negative-biased to ionize the reactive gas and attract the chemically reactive ions toward the cathode. These reactive ions impinge on the substrates in a predominantly vertical direction to produce well defined vertically etched walls.
Inventors
- 👤 Steve Yoneo Muto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:11
CPC Classifications
H; H10; H10P; H10P95/00; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10W; H10W74/00; H10W74/40; H10W74/43
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
132 words
A method of etchng a surface comprising the steps of: positioning the surface to be etched on a first electrode plate; masking the surface to be etched with an etching mask; enclosing in a container the first electrode plate, the surface to be etched and etching mask, and a second electrode plate positioned opposite the first electrode plate; introducing a chemically reactive etchant gas into the container; and electrically biasing the first electrode plate relative to the second electrode plate to ionize the chemically reactive etchant gas in the region between the two plates and to accelerate chemically reactive etchant gas ions toward the first electrode in a direction substanially perpendicular to the surface to be etched, whereby the surface is directionally etched by chemically reactive ions from the chemically reactive gas.
Claim 2
Independent Claim
132 words
A method of etchng a surface comprising the steps of: positioning the surface to be etched on a first electrode plate; masking the surface to be etched with an etching mask; enclosing in a container the first electrode plate, the surface to be etched and etching mask, and a second electrode plate positioned opposite the first electrode plate; introducing a chemically reactive etchant gas into the container; and electrically biasing the first electrode plate relative to the second electrode plate to ionize the chemically reactive etchant gas in the region between the two plates and to accelerate chemically reactive etchant gas ions toward the first electrode in a direction substanially perpendicular to the surface to be etched, whereby the surface is directionally etched by chemically reactive ions from the chemically reactive gas.
Claim 3
Dependent Claim
31 words
A method as in claim 1 wherein the chemically reactive etchant gas is selected from the group consisting of CF 4 , SF 6 , and CCl 2 F 2 .
Claim 4
Dependent Claim
24 words
A method as in claim 2 wherein the step of masking the surface to be etched comprises masking the surface with an aluminum mask.
Claim 5
Dependent Claim
23 words
A method as in claim 2 wherein the container is entirely of metal and including the step of enclosing oxygen in the container.
Claim 6
Dependent Claim
17 words
A method as in claim 1 wherein the chemically reactive etchant gas is a fluoride containing gas.
Claim 7
Dependent Claim
16 words
A method as in claim 1 wherein the chemically reactive gas is a chloride containing gas.
References Cited (Backward Citations)
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US3661747A
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US3816198A
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US3664942A
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US3795557A
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US3935328A
Cited
US3880684A
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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) | 1979-07-27 | 1980-01-26 | 1980-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-27 | 1984-01-26 | 1984-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-27 | 1988-01-26 | 1988-07-27 | $7700.00 | Window Closed / Lapsed |