Patent US2635615A successfully refreshed from Google Patents.
US6090697A
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Etchstop for integrated circuits
Assignee: Texas Instruments Inc
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Filing: 1998-06-26
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Granted: 2000-07-18
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Expires: 2018-06-26
Abstract
Abstract A high-selectivity via etching process. The process includes the steps of: forming an etchstop layer 840 of a material selected from the group consisting of Ti--Al, Ti--Al--N, Ta--Al, Al--N, Ti--Al/Ti--N, Ti--Al--N/Ti--N, Ta--Al/Ti--N, and Ti--Al/Ti--Al--N; forming a dielectric layer over the etchstop layer; and etching the dielectric layer with a fluorine-bearing etchant.
Inventors
- 👤 Guoqiang Xing
- 👤 Glenn A. Cerny
- 👤 Mark R. Visokay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:34
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10D1/692; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/28; H10P50/282; H10P50/283; H10P50/71; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/046; H10W20/071; H10W20/074; H10W20/076; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10P76/00; H10P76/40; H10P76/405
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
141 words
A method for fabricating an integrated circuit including a plurality of metal layers separated by dielectric layers, said method comprising the steps of: (a) forming a first conductive layer; (b) covering said first conductive layer with a conductive etchstop layer; (c) patterning and etching said etchstop layer in a desired pattern; (d) removing portions of said first metal layer not covered by said patterned etchstop layer; (e) depositing an interlevel dielectric layer on said etchstop layer plus first conductive layer; (f) etching a portion of said interlevel dielectric layer above said etchstop layer plus first conductive layer with an etchant that removes said interlevel dielectric layer at least thirty times faster than said etchstop layer to form a via through said interlevel dielectric layer having a bottom on said etchstop layer; and (g) filling said via with a second conductive layer.
Claim 2
Independent Claim
141 words
A method for fabricating an integrated circuit including a plurality of metal layers separated by dielectric layers, said method comprising the steps of: (a) forming a first conductive layer; (b) covering said first conductive layer with a conductive etchstop layer; (c) patterning and etching said etchstop layer in a desired pattern; (d) removing portions of said first metal layer not covered by said patterned etchstop layer; (e) depositing an interlevel dielectric layer on said etchstop layer plus first conductive layer; (f) etching a portion of said interlevel dielectric layer above said etchstop layer plus first conductive layer with an etchant that removes said interlevel dielectric layer at least thirty times faster than said etchstop layer to form a via through said interlevel dielectric layer having a bottom on said etchstop layer; and (g) filling said via with a second conductive layer.
Claim 3
Dependent Claim
34 words
The method of claim 1, wherein said conductive etchstop layer of step (b) of claim 1 is a material selected from the group consisting of Ti--Al, Ti--Al--N, Ta--Al, Al--N, Ti--Al/Ti--N, Ti--Al--N/Ti--N, Ta--Al/Ti--N, and Ti--Al/Ti--Al--N.
Claim 4
Dependent Claim
10 words
The method of claim 2, wherein said material is Ti--Al--N.
Claim 5
Dependent Claim
25 words
The method of claim 3, wherein said Ti--Al--N is (Ti 1-x Al x )--N, where x is in the range of approximately 0.01 to 0.60.
Claim 6
Dependent Claim
10 words
The method of claim 2, wherein said material is Ti--Al.
Claim 7
Dependent Claim
12 words
The method of claim 5, wherein said material is TiAl 3 .
Claim 8
Dependent Claim
18 words
The method of claim 1, wherein the etchant of step (f) of claim 1 is a fluorine-bearing etchant.
Claim 9
Dependent Claim
22 words
The method of claim 7, wherein said interlevel dielectric is silicon dioxide and said fluorine-bearing etchant is Ar/CF 4 /CHF 3 .
Claim 10
Dependent Claim
22 words
The method of claim 7, wherein said interlevel dielectric is silicon nitride and said fluorine-bearing etchant is Ar/CF 4 /O 2 .
Claim 11
Dependent Claim
51 words
A high-selectivity via etching process, comprising the steps of: (a) forming an etchstop layer of a material selected from the group consisting of Ti--Al, Ti--Al--N, Ta--Al, Al--N, Ti--Al/Ti--N, Ti--Al--N/Ti--N, Ta--Al/Ti--N, and Ti--Al/Ti--Al--N; (b) forming a dielectric layer over said etchstop layer; and (c) etching said dielectric layer with a fluorine-bearing etchant.
Claim 12
Dependent Claim
51 words
A high-selectivity via etching process, comprising the steps of: (a) forming an etchstop layer of a material selected from the group consisting of Ti--Al, Ti--Al--N, Ta--Al, Al--N, Ti--Al/Ti--N, Ti--Al--N/Ti--N, Ta--Al/Ti--N, and Ti--Al/Ti--Al--N; (b) forming a dielectric layer over said etchstop layer; and (c) etching said dielectric layer with a fluorine-bearing etchant.
Claim 13
Dependent Claim
10 words
The method of claim 10, wherein said material is Ti--Al--N.
Claim 14
Dependent Claim
25 words
The method of claim 11, wherein said Ti--Al--N is (Ti 1-x Al x )--N, where x is in the range of approximately 0.01 to 0.60.
Claim 15
Dependent Claim
10 words
The method of claim 11, wherein said material is Ti--Al.
Claim 16
Dependent Claim
12 words
The method of claim 13, wherein said material is TiAl 3 .
Claim 17
Dependent Claim
22 words
The method of claim 10, wherein said dielectric layer is silicon dioxide and said fluorine-bearing etchant is Ar/CF 4 /CHF 3 .
Claim 18
Dependent Claim
22 words
The method of claim 10, wherein said dielectric layer is silicon nitride and said fluorine-bearing etchant is Ar/CF 4 /O 2 .
References Cited (Backward Citations)
US4069096A
Cited
US4582564A
Cited
US5231306A
Cited
US5360995A
Cited
US5504041A
Cited
US5609927A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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