US4919748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for tapered etching
Assignee: Agere Systems LLC
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Filing: 1989-06-30
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Granted: 1990-04-24
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Expires: 2009-06-30
Abstract
Abstract A method for etching metal layers including aluminum to create tapered sidewalls is disclosed. The method features the use of trifluoromethane and chlorine in controlled amounts to create a tapered metal layer profile.
Inventors
- 👤 Craig N. Bredbenner
- 👤 Troy A. Giniecki
- 👤 Nur Selamoglu
- 👤 Hans J. Stocker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:20
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/27; H10P70/273; C; C23; C23F; C23F4/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
54 words
A method of semiconductor device fabrication comprising: forming a first layer upon a substrate; forming a second layer containing aluminum upon said first layer; etching both said first and said second layer with a gas mixture, characterized in that said gas mixture contains chlorine and trifluoromethane and said etching step produces a tapered profile.
Claim 2
Independent Claim
54 words
A method of semiconductor device fabrication comprising: forming a first layer upon a substrate; forming a second layer containing aluminum upon said first layer; etching both said first and said second layer with a gas mixture, characterized in that said gas mixture contains chlorine and trifluoromethane and said etching step produces a tapered profile.
Claim 3
Dependent Claim
14 words
The method of claim 1 in which said gas mixture further contains boron trichloride.
Claim 4
Dependent Claim
14 words
The method of claim 1 in which said etching occurs in a plasma environment.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein said first layer is made from a material chosen from the group consisting of: titanium- tungsten and titanium nitride.
Claim 6
Dependent Claim
19 words
The method of claim 1 in which the flow ratio of said trifluoromethane and chlorine is at least 0.75.
Claim 7
Independent Claim
148 words
A method of semiconductor device fabrication comprising: depositing a layer of titanium-tungsten upon a substrate, said layer containing at least five percent titanium by weight; depositing an aluminum rich layer upon said layer of titanium-tungsten layer; covering said aluminum rich layer with an anti reflective coating; covering said anti reflective coating with a patterned mask, said mask having a thickness of 2 μm or less; exposing said aluminum rich layer to boron trichloride; exposing said aluminum rich layer said titanium-tungsten layer in a plasma environment to a mixture of chlorine and trifluoromethane, said chlorine having a flow rate of between 16 and 6 sccm and said trifluoromethane having a flow rate less than 60 sccm, said exposing step creating a polymeric layer in contact with said aluminum rich layer and said titanium tungsten layer and creating a tapered sidewall on said aluminum rich layer and said titanium-tungsten layer;
Claim 8
Independent Claim
148 words
A method of semiconductor device fabrication comprising: depositing a layer of titanium-tungsten upon a substrate, said layer containing at least five percent titanium by weight; depositing an aluminum rich layer upon said layer of titanium-tungsten layer; covering said aluminum rich layer with an anti reflective coating; covering said anti reflective coating with a patterned mask, said mask having a thickness of 2 μm or less; exposing said aluminum rich layer to boron trichloride; exposing said aluminum rich layer said titanium-tungsten layer in a plasma environment to a mixture of chlorine and trifluoromethane, said chlorine having a flow rate of between 16 and 6 sccm and said trifluoromethane having a flow rate less than 60 sccm, said exposing step creating a polymeric layer in contact with said aluminum rich layer and said titanium tungsten layer and creating a tapered sidewall on said aluminum rich layer and said titanium-tungsten layer;
References Cited (Backward Citations)
US4082604A
Cited
US4267013A
Cited
US4256534A
Cited
US4412885A
Cited
US4784719A
Cited
US4838992A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-23 | 1993-10-23 | 1994-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-23 | 1997-10-23 | 1998-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-23 | 2001-10-23 | 2002-04-24 | $7700.00 | Window Closed / Lapsed |