US4970574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromigrationproof structure for multilayer wiring on a semiconductor device
Assignee: NEC Electronics Corp
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Filing: 1989-05-31
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Granted: 1990-11-13
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Expires: 2009-05-31
Abstract
Abstract A multilayer wiring structure for electromigrationproof comprises a first wiring layer and a second wiring layer separated each other by insulating layer. Each of the first and second wiring layers consists of a core portion and a cladding portion. The core portion consists of a metal having a high resistance to electromigration such as gold or a metallic material having gold as the principal constituent. The cladding portion consists of a material having a good adhesion to the insulating layer. Such material is what selected from tungsten (W), titanium-tungsten alloy (TiW) and molybdenum (Mo). The insulating layer preferably consists of organic insulating material having a good surface-flatness such as polyimide.
Inventors
- 👤 Kinji Tsunenari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:17
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/42; H10W20/425; H10W20/44; H10W20/4403; H10W20/4432; H10W20/4435
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
167 words
A multilayer wiring electromigrationproof structure comprising: a first wiring layer formed above a semiconductor substrate and having a protruding contact portion extending toward said semiconductor substrate, so as to be electrically connected thereto, a second wiring layer formed above said first wiring layer and having a protruding contact portion extending toward said first wiring layer so as to be electrically connected thereto, and a polyimide layer separating said first and second wiring layers except for said contact portion connecting therebetween, each of said first and second wiring layers consisting of a gold core layer sheathed with a tungsten cladding layer and a titanium-tungsten alloy cladding layer, said tungsten cladding layer being formed on top and side surfaces of said gold layer while said titanium-tungsten alloy cladding layer is formed on underside surface and said protruding contact portion of said gold core layer such that said titanium-tungsten alloy cladding layer of said second wiring layer is in contact with said tungsten cladding layer of said first wiring layer.
Claim 2
Dependent Claim
167 words
A multilayer wiring electromigrationproof structure comprising: a first wiring layer formed above a semiconductor substrate and having a protruding contact portion extending toward said semiconductor substrate, so as to be electrically connected thereto, a second wiring layer formed above said first wiring layer and having a protruding contact portion extending toward said first wiring layer so as to be electrically connected thereto, and a polyimide layer separating said first and second wiring layers except for said contact portion connecting therebetween, each of said first and second wiring layers consisting of a gold core layer sheathed with a tungsten cladding layer and a titanium-tungsten alloy cladding layer, said tungsten cladding layer being formed on top and side surfaces of said gold layer while said titanium-tungsten alloy cladding layer is formed on underside surface and said protruding contact portion of said gold core layer such that said titanium-tungsten alloy cladding layer of said second wiring layer is in contact with said tungsten cladding layer of said first wiring layer.
Claim 3
Dependent Claim
205 words
A multilayer wiring structure comprising: a semiconductor layer, a first insulating layer formed on said semiconductor layer, said first insulating layer having a first throughhole, a first titanium-tungsten alloy layer selectively formed on said first insulating layer to provide a first wiring pattern, said first titanium-tungsten alloy layer being connected to said semiconductor layer through said first throughhole, a first gold layer formed on said first titanium-tungsten alloy layer, a first tungsten layer formed on top and side surfaces of said first gold layer such that said first gold layer is entirely sheathed with said tungsten layer and said titanium-tungsten layer, a second insulating layer commonly formed on said first insulating layer and said tungsten layer, said second insulating layer having a second throughhole located on said tungsten layer, a second titanium-tungsten alloy layer selectively formed on said second insulating layer to provide a second wiring pattern, said second titanium-tungsten alloy being connected to said first tungsten layer through said second throughhole, a second gold layer formed on said second titanium-tungsten alloy layer, a second tungsten layer formed on top and side surfaces of said second gold layer and a third insulating layer commonly formed on said second insulating layer and said second tungsten layer.
Claim 4
Dependent Claim
205 words
A multilayer wiring structure comprising: a semiconductor layer, a first insulating layer formed on said semiconductor layer, said first insulating layer having a first throughhole, a first titanium-tungsten alloy layer selectively formed on said first insulating layer to provide a first wiring pattern, said first titanium-tungsten alloy layer being connected to said semiconductor layer through said first throughhole, a first gold layer formed on said first titanium-tungsten alloy layer, a first tungsten layer formed on top and side surfaces of said first gold layer such that said first gold layer is entirely sheathed with said tungsten layer and said titanium-tungsten layer, a second insulating layer commonly formed on said first insulating layer and said tungsten layer, said second insulating layer having a second throughhole located on said tungsten layer, a second titanium-tungsten alloy layer selectively formed on said second insulating layer to provide a second wiring pattern, said second titanium-tungsten alloy being connected to said first tungsten layer through said second throughhole, a second gold layer formed on said second titanium-tungsten alloy layer, a second tungsten layer formed on top and side surfaces of said second gold layer and a third insulating layer commonly formed on said second insulating layer and said second tungsten layer.
Claim 5
Dependent Claim
16 words
A multilayer wiring structure according to claim 2, wherein said second insulating film consists of polyimide.
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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) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |