US5519254A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer aluminum wiring in semiconductor IC
Assignee: Yamaha Corp
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Filing: 1994-08-11
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Granted: 1996-05-21
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Expires: 2014-08-11
Abstract
Abstract A lower wiring layer is formed on an insulating film 12 covering a semiconductor substrate 10. The wiring layer 14 has a laminated structure of a barrier metal layer such as WSi2, an Al or Al alloy layer, and a cap metal layer such as WSi2 formed in this order from the bottom. The cap metal layer is caused to contain conductive material such as Al by using an ion injection method or the like. After forming an insulating film covering the wiring layer, a contact hole is formed in the insulating film by a dry etching process using a resist layer as a mask. The dry etching process uses a fluorine based gas such as CHF3 as the etching gas. With this etching gas, fluoride such as Al fluoride (AlF3) is generated to suppress the etching of the cap metal layer.
Inventors
- 👤 Suguru Tabara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:22
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; Y; Y10; Y10S; Y10S148/00; Y10S148/015
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
158 words
A wiring structure used in a semiconductor device, comprising: a substrate including a semiconductor substrate and an insulating layer formed thereon; and a multilayered wiring layer formed on the substrate, including: a first metal layer formed on the substrate, wherein the first metal layer serves as a barrier metal layer; a second metal layer formed on the first metal layer, wherein the second metal layer serves as a main conduction path within the multilayered wiring layer; and a third metal layer formed on the second metal layer that prevents the formation of defects in the second metal layer, wherein a metal substance different from the third metal is present in the third metal layer in a distribution having a concentration which increases toward an interface with the second metal layer, wherein the metal substance is chosen so that if the third metal layer is exposed to a plasma including a fluorine-based gas, the metal substance vapor pressure fluoride.
Claim 2
Dependent Claim
158 words
A wiring structure used in a semiconductor device, comprising: a substrate including a semiconductor substrate and an insulating layer formed thereon; and a multilayered wiring layer formed on the substrate, including: a first metal layer formed on the substrate, wherein the first metal layer serves as a barrier metal layer; a second metal layer formed on the first metal layer, wherein the second metal layer serves as a main conduction path within the multilayered wiring layer; and a third metal layer formed on the second metal layer that prevents the formation of defects in the second metal layer, wherein a metal substance different from the third metal is present in the third metal layer in a distribution having a concentration which increases toward an interface with the second metal layer, wherein the metal substance is chosen so that if the third metal layer is exposed to a plasma including a fluorine-based gas, the metal substance vapor pressure fluoride.
Claim 3
Dependent Claim
29 words
A wiring structure according to claim 1, wherein a primary constituent of the second metal layer is the same as the metal substance distributed in the third metal layer.
Claim 4
Dependent Claim
19 words
A wiring structure according to claim 1, wherein the metal substance distributed in the third metal layer is aluminum.
Claim 5
Dependent Claim
30 words
A wiring structure according to claim 1, wherein the first metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 6
Dependent Claim
27 words
A wiring structure according to claim 1, wherein the second metal layer comprises at least one material selected from a group consisting of aluminum and aluminum alloy.
Claim 7
Dependent Claim
30 words
A wiring structure according to claim 1, wherein the third metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 8
Dependent Claim
19 words
A wiring structure according to claim 1, wherein the first and third metal layers comprise the same metal substance.
Claim 9
Dependent Claim
29 words
A wiring structure according to claim 1, wherein the metal substance distributed in the third metal layer is introduced to the third metal layer by injecting ions of aluminum.
Claim 10
Dependent Claim
20 words
A wiring structure according to claim 8, wherein an amount of aluminum injected is 5×10 15 cm -2 or more.
Claim 11
Dependent Claim
102 words
A wiring structure used in a semiconductor device, comprising: a substrate including a semiconductor substrate and an insulator formed thereon; and a multilayered wiring layer formed on the substrate, including: a barrier metal layer formed on the substrate; an aluminum-based metal layer formed on the barrier metal layer and serving as a main conduction path; and a cap metal layer formed on the aluminum-based metal layer that prevents the formation of defects in the aluminum-based metal layer, wherein aluminum is present in the cap metal layer in a distribution having a concentration which increases toward an interface with the aluminum-based metal layer.
Claim 12
Dependent Claim
102 words
A wiring structure used in a semiconductor device, comprising: a substrate including a semiconductor substrate and an insulator formed thereon; and a multilayered wiring layer formed on the substrate, including: a barrier metal layer formed on the substrate; an aluminum-based metal layer formed on the barrier metal layer and serving as a main conduction path; and a cap metal layer formed on the aluminum-based metal layer that prevents the formation of defects in the aluminum-based metal layer, wherein aluminum is present in the cap metal layer in a distribution having a concentration which increases toward an interface with the aluminum-based metal layer.
Claim 13
Dependent Claim
30 words
A wiring structure according to claim 10, wherein the barrier metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 14
Dependent Claim
30 words
A wiring structure according to claim 10, wherein the cap metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 15
Dependent Claim
27 words
A wiring structure according to claim 10, wherein the aluminum present the cap metal layer is introduced into the cap metal layer by injecting ions of aluminum.
Claim 16
Dependent Claim
20 words
A wiring structure according to claim 13, wherein an amount of aluminum injected is 5×10 15 cm -2 or more.
Claim 17
Dependent Claim
155 words
A wiring structure used for interconnection in a semiconductor device, comprising: (a) a semiconductor substrate; (b) an insulating layer formed over the semiconductor substrate; (c) a lower wiring layer formed over the semiconductor substrate, including: (c-1) a first metal layer formed over the semiconductor substrate, (c-2) a second metal layer formed on the first metal layer for a main conduction path, and (c-3) a third metal layer formed on the second metal layer, wherein a substance different from the third metal is present in the third metal layer in a distribution having a concentration which increases toward an interface with the second metal layer, wherein the substance reacts in the presence of a plasma including a fluorine-based gas to form a fluoride having a low vapor pressure; and (d) an upper wiring layer formed over the lower wiring layer, wherein the upper wiring layer is connected to the lower wiring layer through the insulating layer.
Claim 18
Dependent Claim
155 words
A wiring structure used for interconnection in a semiconductor device, comprising: (a) a semiconductor substrate; (b) an insulating layer formed over the semiconductor substrate; (c) a lower wiring layer formed over the semiconductor substrate, including: (c-1) a first metal layer formed over the semiconductor substrate, (c-2) a second metal layer formed on the first metal layer for a main conduction path, and (c-3) a third metal layer formed on the second metal layer, wherein a substance different from the third metal is present in the third metal layer in a distribution having a concentration which increases toward an interface with the second metal layer, wherein the substance reacts in the presence of a plasma including a fluorine-based gas to form a fluoride having a low vapor pressure; and (d) an upper wiring layer formed over the lower wiring layer, wherein the upper wiring layer is connected to the lower wiring layer through the insulating layer.
Claim 19
Dependent Claim
30 words
A wiring structure according to claim 15, wherein the first metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 20
Dependent Claim
27 words
A wiring structure according to claim 15, wherein the second metal layer comprises at least one material selected from a group consisting of aluminum and aluminum alloy.
Claim 21
Dependent Claim
30 words
A wiring structure according to claim 15, wherein the third metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 22
Dependent Claim
21 words
A wiring structure according to claim 15, wherein the substance present in the distribution in the third metal layer is aluminum.
Claim 23
Dependent Claim
27 words
A wiring structure according to claim 19, wherein the aluminum present in the third metal layer represents aluminum ion injected at 5×10 15 cm -2 or more.
Claim 24
Dependent Claim
27 words
A wiring structure according to claim 15, wherein the upper wiring layer comprises at least one material selected from a group consisting of aluminum and aluminum alloy.
Claim 25
Dependent Claim
14 words
A wiring structure according to claim 15, wherein the insulating layer comprises silicon oxide.
Claim 26
Dependent Claim
130 words
A wiring structure comprising: a substrate including a semiconductor substrate and an insulating layer formed thereon; and a multilayered wiring layer formed over the substrate, including: a first metal layer which serves as a main conduction path within the multilayered wiring layer; and a second metal layer formed on the first metal layer to prevent the formation of defects in the first metal layer, wherein a metal substance different from the second metal is present in the second metal layer in a distribution having a concentration which increases toward an interface with the first metal layer, and wherein the metal substance has the property that if the second metal layer is exposed to a plasma including a fluorine-based gas, the metal substance reacts to form a low vapor pressure fluoride.
Claim 27
Dependent Claim
130 words
A wiring structure comprising: a substrate including a semiconductor substrate and an insulating layer formed thereon; and a multilayered wiring layer formed over the substrate, including: a first metal layer which serves as a main conduction path within the multilayered wiring layer; and a second metal layer formed on the first metal layer to prevent the formation of defects in the first metal layer, wherein a metal substance different from the second metal is present in the second metal layer in a distribution having a concentration which increases toward an interface with the first metal layer, and wherein the metal substance has the property that if the second metal layer is exposed to a plasma including a fluorine-based gas, the metal substance reacts to form a low vapor pressure fluoride.
Claim 28
Dependent Claim
27 words
A wiring structure according to claim 23, wherein the first metal layer comprises at least one material selected from a group consisting of aluminum and aluminum alloy.
Claim 29
Dependent Claim
30 words
A wiring structure according to claim 24, wherein the second metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 30
Dependent Claim
13 words
A wiring structure according to claim 25, wherein the metal substance is aluminum.
Claim 31
Dependent Claim
29 words
A wiring structure according to claim 23, wherein the metal substance includes at least one constituent selected from the group of Al, Cr, Sr, Cu, Ni, Mg and Ti.
Claim 32
Dependent Claim
30 words
A wiring structure according to claim 23, wherein the metal substance is distributed within the second metal layer so as to have a peak concentration within the second metal layer.
Claim 33
Dependent Claim
29 words
A wiring structure according to claim 1, wherein the metal substance includes at least one constituent selected from the group of Al, Cr, Sr, Cu, Ni, Mg and Ti.
Claim 34
Dependent Claim
37 words
A wiring structure according to claim 15, wherein the substance present in the distribution in the third metal layer includes at least one constituent selected from the group of Al, Cr, Sr, Cu, Ni, Mg and Ti.
Claim 35
Dependent Claim
30 words
A wiring structure according to claim 1, wherein the metal substance is distributed within the third metal layer so as to have a peak concentration within the third metal layer.
Claim 36
Dependent Claim
29 words
A wiring structure according to claim 10, wherein the aluminum is distributed within the cap metal layer so as to have a peak concentration within the cap metal layer.
Claim 37
Dependent Claim
30 words
A wiring structure according to claim 15, wherein the metal substance is distributed within the third metal layer so as to have a peak concentration within the third metal layer.
Claim 38
Dependent Claim
27 words
A wiring structure according to claim 26, wherein the aluminum present in the second metal layer represents aluminum ion injected at 5×10 15 cm -2 or more.
Claim 39
Dependent Claim
110 words
A wiring structure comprising: a substrate including a semiconductor substrate and an insulating layer formed thereon; and a multilayered wiring layer formed over the substrate, including: a first metal layer which serves as a main conduction path within the multilayered wiring layer; and a second metal layer formed on the first metal layer to prevent the formation of defects in the first metal layer when the second metal layer is exposed to a plasma including a fluorine-based gas, wherein a metal substance different from the second metal is present in the second metal layer in a distribution having a concentration which increases toward an interface with the first metal layer.
Claim 40
Dependent Claim
110 words
A wiring structure comprising: a substrate including a semiconductor substrate and an insulating layer formed thereon; and a multilayered wiring layer formed over the substrate, including: a first metal layer which serves as a main conduction path within the multilayered wiring layer; and a second metal layer formed on the first metal layer to prevent the formation of defects in the first metal layer when the second metal layer is exposed to a plasma including a fluorine-based gas, wherein a metal substance different from the second metal is present in the second metal layer in a distribution having a concentration which increases toward an interface with the first metal layer.
Claim 41
Dependent Claim
27 words
A wiring structure according to claim 35, wherein the first metal layer comprises at least one material selected from a group consisting of aluminum and aluminum alloy.
Claim 42
Dependent Claim
30 words
A wiring structure according to claim 36, wherein the second metal layer comprises at least one material selected from a group consisting of WSi 2 , MoSi 2 and TiW.
Claim 43
Dependent Claim
13 words
A wiring structure according to claim 37, wherein the metal substance is aluminum.
Claim 44
Dependent Claim
27 words
A wiring structure according to claim 38, wherein the aluminum present in the second metal layer represents aluminum ion injected at 5×10 15 cm -2 or more.
Claim 45
Dependent Claim
29 words
A wiring structure according to claim 35, wherein the metal substance includes at least one constituent selected from the group of Al, Cr, Sr, Cu, Ni, Mg and Ti.
Claim 46
Dependent Claim
30 words
A wiring structure according to claim 35, wherein the metal substance is distributed within the second metal layer so as to have a peak concentration within the second metal layer.
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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) | 1999-05-21 | 1999-11-20 | 2000-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-21 | 2003-11-20 | 2004-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-21 | 2007-11-20 | 2008-05-21 | $7700.00 | Window Closed / Lapsed |