Patent US4678540A successfully refreshed from Google Patents.
US4678540A
Expired / Lapsed
US
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Plasma etch process
Assignee: Motorola Solutions Inc
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Filing: 1986-06-09
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Granted: 1987-07-07
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Expires: 2006-06-09
Abstract
Abstract In an aluminum etch process using SiCl 4 in a plasma reactor, edge profile is controlled by adding predetermined amounts of nitrogen and chlorine. The resulting aniosotropic etch causes walls to have a 60°-90° angle with respect to the substrate. Edge profile is further controlled by tapering the photoresist mask, e.g. by baking
Inventors
- 👤 David H. Uchimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:20
CPC Classifications
C; C23; C23F; C23F4/00; H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
105 words
In a process for etching aluminum material through a mask, and the mask erodes during the process, by contacting the aluminum material with a plasma formed in a first gaseous etchant, the improvement comprising the steps of: forming a sloping, non-vertical sidewall on the exposed edges of said mask; and then supplying a nitrogen, second gaseous etchant which reacts selectively with said mask; and simultaneously supplying a chlorine, third gaseous etchant which reacts selectively with said material; and controlling the proportion of said supplied second and third etchants to produce a predetermined transfer of slope from said mask to the sidewall formed in said material.
Claim 2
Dependent Claim
105 words
In a process for etching aluminum material through a mask, and the mask erodes during the process, by contacting the aluminum material with a plasma formed in a first gaseous etchant, the improvement comprising the steps of: forming a sloping, non-vertical sidewall on the exposed edges of said mask; and then supplying a nitrogen, second gaseous etchant which reacts selectively with said mask; and simultaneously supplying a chlorine, third gaseous etchant which reacts selectively with said material; and controlling the proportion of said supplied second and third etchants to produce a predetermined transfer of slope from said mask to the sidewall formed in said material.
Claim 3
Dependent Claim
15 words
The process as set forth in claim 1 wherein said mask comprises a photoresist material.
Claim 4
Dependent Claim
16 words
The process as set forth in claim 2 wherein said forming step comprises heating said photoresist.
Claim 5
Dependent Claim
34 words
The process as set forth in claim 3 wherein said first gaseous etchant comprises SiCl 4 , said second gaseous etchant comprises N 2 , and said third gaseous etchant comprises Cl 2 .
Claim 6
Dependent Claim
28 words
The process as set forth in claim 4 wherein the flow rates of said second and third etchants are in the ratio of from 6:1 to 2:3 respectively.
Claim 7
Dependent Claim
28 words
The process as set forth in claim 1 wherein the flow rates of said second and third etchants are in the ratio of from 6:1 to 2:3 respectively.
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) | 1990-07-06 | 1991-01-05 | 1991-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-06 | 1995-01-05 | 1995-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-06 | 1999-01-05 | 1999-07-07 | $7700.00 | Window Closed / Lapsed |