US5847459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-level wiring using refractory metal
Assignee: Fujitsu Semiconductor Ltd
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Filing: 1995-07-17
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Granted: 1998-12-08
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Expires: 2015-07-17
Abstract
Abstract A multi-level wiring structure having: a first wiring formed on an insulating surface, the first wiring containing refractory metal as a main composition thereof; an inter-level insulating film formed to cover the first wiring and having a contact hole at a predetermined region of the first wiring; a second wiring formed over said inter-level insulating film to be electrically connected to an upper surface of the first wiring at a region of the contact hole, the second wiring containing Al as a main composition thereof; and a barrier layer disposed at an interface where the first and second wirings are electrically connected, the barrier layer being made of a material different from, and substantially not reacting with, both Al and the refractory metal constituting the main composition of the first wiring. It is possible to suppress an increase of contact resistance between an upper level wiring and a lower level wiring even if refractory metal is used as the lower level wiring and heat treatment is performed after the upper level wiring is formed.
Inventors
- 👤 Toshio Taniguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:34
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4437; H10W20/4441; H10W20/425; Y; Y10; Y10S; Y10S438/00; Y10S438/927
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
165 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, the refractory metal being selected from the group consisting of W, WSi, Ta, TiN, and TiN/Ti, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole for flowing current therethrough; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal.
Claim 2
Dependent Claim
165 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, the refractory metal being selected from the group consisting of W, WSi, Ta, TiN, and TiN/Ti, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole for flowing current therethrough; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal.
Claim 3
Dependent Claim
35 words
A semiconductor device according to claim 1, wherein said barrier layer includes one or more layers selected from a group consisting of a TiN layer, a TiW layer, a W layer, and a Ta layer.
Claim 4
Dependent Claim
170 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, said device further comprising an oxidized surface layer formed on a surface of said barrier layer by slightly oxidizing a surface of said barrier layer.
Claim 5
Dependent Claim
170 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, said device further comprising an oxidized surface layer formed on a surface of said barrier layer by slightly oxidizing a surface of said barrier layer.
Claim 6
Dependent Claim
16 words
A semiconductor device according to claim 3, wherein said barrier Layer is a first TiN layer.
Claim 7
Dependent Claim
170 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, wherein said barrier layer includes a first layer comprising Ti and a second layer comprising TiN, said second layer being formed on the first layer.
Claim 8
Dependent Claim
170 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, wherein said barrier layer includes a first layer comprising Ti and a second layer comprising TiN, said second layer being formed on the first layer.
Claim 9
Dependent Claim
170 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, wherein said barrier layer includes a first layer comprising TiN and a second layer comprising Ti, said second layer being formed on the first layer.
Claim 10
Dependent Claim
170 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, wherein said barrier layer includes a first layer comprising TiN and a second layer comprising Ti, said second layer being formed on the first layer.
Claim 11
Dependent Claim
19 words
A semiconductor device according to claim 6, wherein said second wiring has a Ti concentration of 0.1% or smaller.
Claim 12
Dependent Claim
16 words
A semiconductor device according to claim 4, wherein said first TiN layer has a (200) orientation.
Claim 13
Dependent Claim
18 words
A semiconductor device according to claim 4, further comprising a second TiN layer formed on said second wiring.
Claim 14
Dependent Claim
21 words
A semiconductor device according to claim 1, wherein said contact hole in said second insulating layer has a rounded upper edge.
Claim 15
Dependent Claim
159 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, wherein said barrier layer comprises a single TiN layer having an oxidized surface layer.
Claim 16
Dependent Claim
159 words
A semiconductor device comprising: an underlie having a first insulating layer; a first wiring comprising 90% or more of refractory metal, said first wiring being disposed on said first insulating layer; a second insulating layer formed on said first wiring and having a contact hole on a desired region of the first wiring; a second wiring comprising 90% or more of Al, said second wiring being disposed on said second insulating layer to be electrically connected to an upper surface of said first wiring at a region of said contact hole; and a barrier layer formed between said first and second wirings at a portion where said first and second wirings are electrically connected, said barrier layer being made of a material different from, and having a degree of reactivity which does not significantly effect the contact resistance between, the Al and the refractory metal, wherein said barrier layer comprises a single TiN layer having an oxidized surface layer.
Claim 17
Dependent Claim
24 words
A semiconductor device as recited in claim 11, wherein said oxidized surface layer is in contact with the first wiring and the second wiring.
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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) | 2001-12-07 | 2002-06-08 | 2002-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-07 | 2006-06-08 | 2006-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-07 | 2010-06-08 | 2010-12-08 | $7700.00 | Window Closed / Lapsed |