US4547261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anisotropic etching of aluminum
Assignee: Intersil Corp
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Filing: 1984-09-28
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Granted: 1985-10-15
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Expires: 2004-09-28
Abstract
Abstract An improved etchant gas composition for the plasma etching of a layer of aluminum or its alloys on a substrate is provided. The etchant composition comprises boron trichloride, nitrogen and a halogenated fluorocarbon. In addition to providing an efficient, anisotropic etch, the subject etchant compositions form a passivating coating on aluminum reactor walls, protecting them from being etched and substantially reducing contamination problems. The subject compositions etch aluminum/silicon alloys without leaving a residue of slilicon "freckles" on the substrate surface.
Inventors
- 👤 Jer-shen Maa
- 👤 Bernard Halon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:00
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: 10
Claim 1
Independent Claim
17 words
A gaseous etchant composition for aluminum and its alloys comprising boron trichloride, nitrogen and a halogenated fluorocarbon.
Claim 2
Dependent Claim
17 words
A gaseous etchant composition for aluminum and its alloys comprising boron trichloride, nitrogen and a halogenated fluorocarbon.
Claim 3
Dependent Claim
23 words
An etchant composition in accordance with claim 1, wherein the halogenated fluorocarbon is selected from the group consisting of chlorotrifluoromethane, dichlorodifluoromethane and trichlorofluoromethane.
Claim 4
Dependent Claim
14 words
An etchant composition in accordance with claim 2, wherein said halogenated fluorocarbon is chlorotrifluoromethane.
Claim 5
Dependent Claim
14 words
An etchant composition in accordance with claim 2, wherein said halogenated fluorocarbon is dichlorodifluoromethane.
Claim 6
Dependent Claim
14 words
An etchant composition in accordance with claim 2, wherein said halogenated fluorocarbon is trichlorofluoromethane.
Claim 7
Dependent Claim
47 words
An etchant composition in accordance with claim 1, wherein said composition contains, on a volume basis, from about 25 to about 46 percent of boron trichloride, from about 25 to about 46 percent of nitrogen and from about 8 to about 50 percent of the halogenated fluorocarbon.
Claim 8
Dependent Claim
36 words
In a process of plasma etching aluminum or an alloy thereof on a substrate with an etchant gas, the improvement comprising utilizing as the etchant gas a mixture of boron trichloride, nitrogen and a halogenated fluorocarbon.
Claim 9
Dependent Claim
36 words
In a process of plasma etching aluminum or an alloy thereof on a substrate with an etchant gas, the improvement comprising utilizing as the etchant gas a mixture of boron trichloride, nitrogen and a halogenated fluorocarbon.
Claim 10
Dependent Claim
22 words
A process in accordance with claim 7, wherein the halogenated fluorocarbon is selected from the group consisting of chlorotrifluoromethane, dichlorodifluoromethane and trichlorofluoromethane.
References Cited (Backward Citations)
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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) | 1988-10-14 | 1989-04-15 | 1989-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-14 | 1993-04-15 | 1993-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-14 | 1997-04-15 | 1997-10-15 | $7700.00 | Window Closed / Lapsed |