US4522681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for tapered dry etching
Assignee: General Electric Co
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Filing: 1984-04-23
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Granted: 1985-06-11
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Expires: 2004-04-23
Abstract
Abstract Holes in substrates are produced by a photolithography-plasma dry etching method employing a positive photoresist mask such as poly(methyl methacrylate) which is capable of being isotropically eroded by plasma action. The result is simultaneous anisotropic etching of the substrate and isotropic erosion of the mask, producing tapered holes.
Inventors
- 👤 Bernard Gorowitz
- 👤 Richard J. Saia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:10
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/094; H10P50/73
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
80 words
A dry etching method which comprises the steps of: (A) forming on a substrate a positive mask having substantially vertical edges from a polymeric photoresist material capable of being isotropically eroded by plasma action; (B) contacting the masked substrate with a plasma under conditions producing both anisotropic etching of said substrate and controlled isotropic erosion of said mask, and continuing plasma contact until the desired end point has been reached, thereby producing at least one tapered hole in said substrate.
Claim 2
Dependent Claim
80 words
A dry etching method which comprises the steps of: (A) forming on a substrate a positive mask having substantially vertical edges from a polymeric photoresist material capable of being isotropically eroded by plasma action; (B) contacting the masked substrate with a plasma under conditions producing both anisotropic etching of said substrate and controlled isotropic erosion of said mask, and continuing plasma contact until the desired end point has been reached, thereby producing at least one tapered hole in said substrate.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein the photoresist material is poly(methyl methacrylate).
Claim 4
Dependent Claim
14 words
A method according to claim 2 wherein the substrate is an inorganic dielectric material.
Claim 5
Dependent Claim
20 words
A method according to claim 2 wherein the plasma comprises at least one fluorine compound and at least one oxidizer.
Claim 6
Dependent Claim
21 words
A method according to claim 4 wherein the fluorine compound is at least one of trifluoromethane, tetrafluoromethane, hexafluoroethane and nitrogen trifluoride.
Claim 7
Dependent Claim
16 words
A method according to claim 5 wherein at least a portion of the oxidizer is oxygen.
Claim 8
Dependent Claim
13 words
A method according to claim 6 wherein the dielectric material is silicon dioxide.
Claim 9
Independent Claim
94 words
A method for dry etching a silicon dioxide substrate which comprises the steps of forming on said substrate a positive poly(methyl methacrylate) mask having substantially vertical edges, and contacting the masked substrate under plasma etching conditions with a plasma comprising oxygen and at least one fluorine compound selected from the group consisting of trifluoromethane, tetrafluoromethane and hexafluoroethane, thereby producing both anisotropic etching of said substrate and controlled isotropic erosion of said mask, and continuing plasma contact until the desired end point has been reached, thereby producing at least one tapered hole in said substrate.
Claim 10
Independent Claim
94 words
A method for dry etching a silicon dioxide substrate which comprises the steps of forming on said substrate a positive poly(methyl methacrylate) mask having substantially vertical edges, and contacting the masked substrate under plasma etching conditions with a plasma comprising oxygen and at least one fluorine compound selected from the group consisting of trifluoromethane, tetrafluoromethane and hexafluoroethane, thereby producing both anisotropic etching of said substrate and controlled isotropic erosion of said mask, and continuing plasma contact until the desired end point has been reached, thereby producing at least one tapered hole in said substrate.
Claim 11
Dependent Claim
12 words
A method according to claim 8 wherein the fluorine compound is hexafluoroethane.
Claim 12
Independent Claim
79 words
A method for dry etching a silicon dioxide substrate which comprises the steps of forming on said substrate a positive poly(methyl methacrylate) mask having substantially vertical edges, and contacting the masked substrate under reactive ion etching conditions with a plasma comprising nitrogen trifluoride, thereby producing both anisotropic etching of said substrate and controlled isotropic erosion of said mask, and continuing plasma contact until desired end point has been reached, thereby producing at least one tapered hole in said substrate.
Claim 13
Independent Claim
79 words
A method for dry etching a silicon dioxide substrate which comprises the steps of forming on said substrate a positive poly(methyl methacrylate) mask having substantially vertical edges, and contacting the masked substrate under reactive ion etching conditions with a plasma comprising nitrogen trifluoride, thereby producing both anisotropic etching of said substrate and controlled isotropic erosion of said mask, and continuing plasma contact until desired end point has been reached, thereby producing at least one tapered hole in said substrate.
Claim 14
Dependent Claim
12 words
A method according to claim 10 wherein the plasma also contains oxygen.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |