US4030967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gaseous plasma etching of aluminum and aluminum oxide
Assignee: Nortel Networks Ltd
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Filing: 1976-08-16
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Granted: 1977-06-21
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Expires: 1996-08-16
Abstract
Abstract Gaseous plasma etching of aluminum with conventional plasma etch gases has not hitherto been commercially possible due to a layer of aluminum oxide (Al 2 O 3 ) which forms on freshly prepared aluminum surfaces. By first plasma etching in the presence of a gaseous trihalide, preferably in a so-called "pancake" or radial-flow type reactor, the oxide layer is removed. Aluminum etching can then continue, either with or without plasma conditions, depending upon the etch gas used.
Inventors
- 👤 Sidney Ivor Joseph Ingrey
- 👤 Heinz Josef Nentwich
- 👤 Robert Gordon Poulsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:35
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/27; H10P70/273; C; C23; C23F; C23F4/00; C23G; C23G5/00; H10P50/00; H10P50/20; H10P50/26; H10P50/262; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
32 words
A process for gaseous etching of aluminum and aluminum oxide, including an initial step of plasma etching in the presence of a gaseous trihalide comprising at least in part, a boron trihalide.
Claim 2
Dependent Claim
32 words
A process for gaseous etching of aluminum and aluminum oxide, including an initial step of plasma etching in the presence of a gaseous trihalide comprising at least in part, a boron trihalide.
Claim 3
Dependent Claim
40 words
A process as claimed in claim 1, including continuing the gaseous plasma etch until any surface layer of aluminum oxide is removed from an underlying layer of aluminum, and further including the step of gaseous plasma etching said aluminum layer.
Claim 4
Dependent Claim
39 words
A process as claimed in claim 1, including continuing the gaseous plasma etch until any surface layer of aluminum oxide is removed from an underlying layer of aluminum, and further including the step of gaseous etching said aluminum layer.
Claim 5
Dependent Claim
18 words
A process as claimed in claim 3, said step of gaseous etching said aluminum layer using gaseous chlorine.
Claim 6
Dependent Claim
25 words
A process as claimed in claim 1, including the addition of gaseous chloride after a predetermined period of etching in the presence of said trihalide.
Claim 7
Dependent Claim
31 words
A process as claimed in claim 1, for the production of semiconductor devices on a structure comprising an aluminum layer on an insulating layer over a substrate, including the steps of:
Claim 8
Dependent Claim
49 words
defining a desired pattern to be formed in the aluminum layer by plasma etch resist mask; 2. plasma etching said structure in the presence of said gaseous trihalide to remove any aluminum oxide layer on said aluminum layer; 3. gaseous etching said aluminum layer through to said insulating layer.
Claim 9
Dependent Claim
49 words
defining a desired pattern to be formed in the aluminum layer by plasma etch resist mask; 2. plasma etching said structure in the presence of said gaseous trihalide to remove any aluminum oxide layer on said aluminum layer; 3. gaseous etching said aluminum layer through to said insulating layer.
Claim 10
Dependent Claim
14 words
A process as claimed in claim 6, said boron trihalide being BCl 3 .
Claim 11
Dependent Claim
16 words
A process as claimed in claim 6, including the addition of chlorine gas after step (2).
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) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |