US5316974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit copper metallization process using a lift-off seed layer and a thick-plated conductor layer
Assignee: Texas Instruments Inc
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Filing: 1990-04-30
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Granted: 1994-05-31
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Expires: 2010-04-30
Abstract
Abstract An improved metallized structure (10) is formed from a copper seed layer (46) and a copper structure (48). Semiconductor devices to be connected (16-18) are covered by a conductive barrier layer (20). An oxide layer (28) is then deposited over the barrier layer (20) and patterned using standard photolithographic techniques and an anisotropic plasma etch. Vertical sidewalls (36-38) are formed by the etch and an HF deglaze. A seed layer (44-46) is then sputtered onto a photoresist layer (30) and the exposed barrier layer (20). After stripping the photoresist (30) and the seed layer (44) thereon, the copper structure (48) is electroplated over the remaining seed layer (46). The structure (48) thus formed has approximately vertical sidewalls (24-26) for improved contact with subsequent layers.
Inventors
- 👤 Sue E. Crank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:18
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W20/00; H10W20/01; H10W20/031; Y; Y10; Y10S; Y10S438/00; Y10S438/963
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
97 words
A method for forming a conductive structure in an integrated circuit, comprising the steps of: forming a conductive barrier layer in conductive contact with components in a semiconductor substrate; forming an insulating layer on said barrier layer; forming a patterned layer on said insulating layer; etching said insulating layer using said patterned layer as an etch mask, said etching exposing a portion of said barrier layer; depositing a seed layer overall; removing said patterned layer, thereby removing the portion of said seed layer deposited on said patterned layer; and selectively forming a conductor on said seed layer.
Claim 2
Independent Claim
97 words
A method for forming a conductive structure in an integrated circuit, comprising the steps of: forming a conductive barrier layer in conductive contact with components in a semiconductor substrate; forming an insulating layer on said barrier layer; forming a patterned layer on said insulating layer; etching said insulating layer using said patterned layer as an etch mask, said etching exposing a portion of said barrier layer; depositing a seed layer overall; removing said patterned layer, thereby removing the portion of said seed layer deposited on said patterned layer; and selectively forming a conductor on said seed layer.
Claim 3
Dependent Claim
13 words
A method as in claim 1 wherein said insulating layer comprises silicon dioxide.
Claim 4
Dependent Claim
16 words
A method as in claim 1 wherein said seed layer and said conductor layer comprise copper.
Claim 5
Dependent Claim
12 words
A method as in claim 1 wherein said barrier layer comprises tantalum.
Claim 6
Dependent Claim
24 words
A method as in claim 1 wherein said etching of said insulating layer etches a portion of said insulating layer beneath said patterned layer.
Claim 7
Dependent Claim
20 words
A method as in claim 1 wherein said patterned layer comprises photoresist and said patterned layer is patterned using photolithography.
Claim 8
Independent Claim
118 words
A method for forming a conductive structure in an integrated circuit, comprising the steps of: forming a conductive barrier layer in conductive contact with components in a semiconductor substrate; forming an insulating layer on said barrier layer; forming a patterned layer on said insulating layer; etching said insulating layer using said patterned layer as an etch mask, said etching exposing a portion of said barrier layer; depositing a seed layer overall; removing said patterned layer, thereby removing the portion of said seed layer deposited on said patterned layer; selectively forming a conductor on said seed layer; removing said insulating layer after the formation of said conductor; and etching said barrier layer using said conductor as an etch mask.
Claim 9
Independent Claim
118 words
A method for forming a conductive structure in an integrated circuit, comprising the steps of: forming a conductive barrier layer in conductive contact with components in a semiconductor substrate; forming an insulating layer on said barrier layer; forming a patterned layer on said insulating layer; etching said insulating layer using said patterned layer as an etch mask, said etching exposing a portion of said barrier layer; depositing a seed layer overall; removing said patterned layer, thereby removing the portion of said seed layer deposited on said patterned layer; selectively forming a conductor on said seed layer; removing said insulating layer after the formation of said conductor; and etching said barrier layer using said conductor as an etch mask.
Claim 10
Dependent Claim
13 words
A method as in claim 7 wherein said insulating layer comprises silicon dioxide.
Claim 11
Dependent Claim
16 words
A method as in claim 7 wherein said seed layer and said conductor layer comprise copper.
Claim 12
Dependent Claim
12 words
A method as in claim 7 wherein said barrier layer comprises tantalum.
Claim 13
Dependent Claim
24 words
A method as in claim 7 wherein said etching of said insulating layer etches a portion of said insulating layer beneath said patterned layer.
Claim 14
Dependent Claim
20 words
A method as in claim 7 wherein said patterned layer comprises photoresist and said patterned layer is patterned using photolithography.
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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) | 1997-05-30 | 1997-11-29 | 1998-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-30 | 2001-11-29 | 2002-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-30 | 2005-11-29 | 2006-05-31 | $7700.00 | Window Closed / Lapsed |