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US5350488A
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Process for etching high copper content aluminum films
Assignee: Applied Materials Inc
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Filing: 1992-12-10
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Granted: 1994-09-27
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Expires: 2012-12-10
Abstract
Abstract Aluminum alloys containing high amounts of copper can be etched to eliminate copper residues using boron trichloride and chlorine under etch conditions of low temperature, low pressure, high power and strict control of the amount of nitrogen present.
Inventors
- 👤 Elaine A. Webb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:56
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: 12
Claim 1
Independent Claim
56 words
A method for reactive ion etching of an aluminum alloy containing over about 0.5% of copper on a substrate which comprises etching with a precursor gas including boron trichloride and chlorine at temperatures below about 80° C. while regulating the nitrogen content of the precursor gases to prevent formation of a copper residue on the substrate.
Claim 2
Independent Claim
56 words
A method for reactive ion etching of an aluminum alloy containing over about 0.5% of copper on a substrate which comprises etching with a precursor gas including boron trichloride and chlorine at temperatures below about 80° C. while regulating the nitrogen content of the precursor gases to prevent formation of a copper residue on the substrate.
Claim 3
Dependent Claim
17 words
A method according to claim 1 wherein the temperature is maintained at about 60°-65° C. during etching.
Claim 4
Dependent Claim
26 words
A method according to claim 1 wherein said aluminum alloy has a layer selected from the group consisting of TiN, TiW and W thereover or thereunder.
Claim 5
Dependent Claim
16 words
A method according to claim 3 wherein said aluminum alloy has a layer of TiN thereover.
Claim 6
Dependent Claim
23 words
A method according to claim 1 wherein the pressure during etching is maintained at a level of about 10 to about 30 millitorr.
Claim 7
Independent Claim
58 words
A method of reactive ion etching an aluminum layer containing about 1% by weight of copper on a substrate using boron trichloride and chlorine as the etch gases at a maximum temperature of about 100° C. comprising regulating the amount of nitrogen carrier gas during etching so that formation of a copper residue on the substrate is avoided.
Claim 8
Independent Claim
58 words
A method of reactive ion etching an aluminum layer containing about 1% by weight of copper on a substrate using boron trichloride and chlorine as the etch gases at a maximum temperature of about 100° C. comprising regulating the amount of nitrogen carrier gas during etching so that formation of a copper residue on the substrate is avoided.
Claim 9
Dependent Claim
15 words
A method according to claim 6 wherein the aluminum has a layer of TiN thereover.
Claim 10
Independent Claim
57 words
A method of reactive ion etching an aluminum layer containing about 2% by weight of copper on a substrate using boron trichloride and chlorine as the etch gases at a maximum temperature of about 100° C. comprising etching by regulating the amount of nitrogen present so that formation of a copper residue on the substrate is avoided.
Claim 11
Independent Claim
57 words
A method of reactive ion etching an aluminum layer containing about 2% by weight of copper on a substrate using boron trichloride and chlorine as the etch gases at a maximum temperature of about 100° C. comprising etching by regulating the amount of nitrogen present so that formation of a copper residue on the substrate is avoided.
Claim 12
Dependent Claim
15 words
A method according to claim 8 wherein the aluminum has a layer of TiN thereover.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-09-26 | 1998-03-28 | 1998-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-26 | 2002-03-28 | 2002-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-26 | 2006-03-28 | 2006-09-27 | $7700.00 | Window Closed / Lapsed |