EP0273629A2
Expired / Lapsed
EP
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Transition metal clad interconnect for integrated circuits
Assignee: Inmos Corp
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Filing: 1987-12-14
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Granted: —
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Expires: 2007-12-14
Abstract
Abstract An integrated circuit includes a patterned aluminum based interconnect clad on the top (15) and side portions (18,20) with a layer of transition metal (16,22). The cladding of transition metal prevents the formation of both vertical hillocks and lateral protrusions. Preventing these formations increases the reliability of an interconnect by significantly reducing passivation cracking and electrical shorting between interconnects which result from vertical hillock and lateral protrusion formations.
Inventors
- 👤 Robert Edwin Jones, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 12:23
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/40; H10W20/41; H10W20/425
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
84 words
An interconnect for an integrated circuit having a substrate, comprising an interconnect member (10) formed of an aluminum-based metal established on the substrate and patterned into a desired interconnection pattern having a top surface (15) and side surfaces (18,20); and a conformal layer (22) of a transition metal established over the patterned interconnect member (10) to cover the top (15) and sides (18,20) of the patterned interconnect member (10) such that the transition metal covering prevents the formation of vertical hillocks and lateral protrusions.
Claim 2
Dependent Claim
84 words
An interconnect for an integrated circuit having a substrate, comprising an interconnect member (10) formed of an aluminum-based metal established on the substrate and patterned into a desired interconnection pattern having a top surface (15) and side surfaces (18,20); and a conformal layer (22) of a transition metal established over the patterned interconnect member (10) to cover the top (15) and sides (18,20) of the patterned interconnect member (10) such that the transition metal covering prevents the formation of vertical hillocks and lateral protrusions.
Claim 3
Dependent Claim
30 words
An interconnect as claimed in Claim 1 wherein said interconnect member (10) comprises a homogeneous alloy of aluminum-silicon in which the silicon concentration is between 0.5 to 2.0 weight percent.
Claim 4
Dependent Claim
40 words
An interconnect as claimed in Claim 1 wherein said interconnect member comprises a homogeneous alloy of aluminum-silicon-titanium in which the silicon concentration is between 0.5 to 2.0 weight percent and the titanium concentration is between 0.1 and 0.5 weight percent.
Claim 5
Dependent Claim
25 words
An interconnect as claimed in Claim 1 wherein said interconnect member comprises a composite structure of alternating layers of titanium and layers of aluminum alloys.
Claim 6
Dependent Claim
34 words
An interconnect as claimed in any preceding claim further comprising a base located beneath said interconnect member (10), said base comprising a diffusion barrier layer that is patterned together with said interconnect member (10).
Claim 7
Dependent Claim
14 words
An interconnect as claimed in Claim 5 wherein said diffusion barrier is titanium nitride.
Claim 8
Dependent Claim
34 words
An interconnect as claimed in any preceding claim wherein said transition metal on said top surface (15) is the same as said transition metal on said side surfaces (18,20) of said interconnect member (10).
Claim 9
Dependent Claim
23 words
An interconnect as claimed in Claim 7 wherein said transition metal on said top surface (15) and said side surfaces (18,20) is titanium.
Claim 10
Dependent Claim
32 words
An interconnect as claimed in Claim 1 wherein said transition metal on said top surface (15) is different from said transition metal on said side surfaces (18,20) of said interconnect member (10).
Claim 11
Dependent Claim
34 words
An interconnect as claimed in Claim 9 wherein said transition metal on said top surface (15) is titanium and said transition metal on said side surfaces (18,20) of said interconnect member (10) is tungsten.
Claim 12
Independent Claim
132 words
A method of forming an interconnect for an integrated circuit comprising forming an interconnect film (14) on an integrated circuit surface (12); forming a transition metal layer (16) on top of the interconnect film (14); etching the transition metal (16) and interconnect film (14) to form a patterned interconnect member (10) having side surfaces (18,20) and a top layer (15) of the first transition metal; forming a conformal layer (22) of transition metal on the patterned interconnect member to cover the top layer (15) and sides (18,20) of the patterned interconnect member (10); anisotropically etching the conformal layer (22) to remove the transition metal from surface areas (24,26) adjacent the interconnect member (10) without removing all the transition metal from the top layer (15) and sides (18,20) of the interconnect member (10).
Claim 13
Independent Claim
132 words
A method of forming an interconnect for an integrated circuit comprising forming an interconnect film (14) on an integrated circuit surface (12); forming a transition metal layer (16) on top of the interconnect film (14); etching the transition metal (16) and interconnect film (14) to form a patterned interconnect member (10) having side surfaces (18,20) and a top layer (15) of the first transition metal; forming a conformal layer (22) of transition metal on the patterned interconnect member to cover the top layer (15) and sides (18,20) of the patterned interconnect member (10); anisotropically etching the conformal layer (22) to remove the transition metal from surface areas (24,26) adjacent the interconnect member (10) without removing all the transition metal from the top layer (15) and sides (18,20) of the interconnect member (10).
Claim 14
Dependent Claim
32 words
A method as claimed in Claim 11 wherein said interconnect film (14) comprises aluminum, or an aluminum alloy or a laminate structure having alternating layers of transition metal and an aluminum alloy.
Claim 15
Dependent Claim
23 words
A method as claimed in Claim 11 or 12 wherein said integrated circuit surface (12) comprises a substrate material or a dielectric material.
Claim 16
Dependent Claim
37 words
The method as claimed in Claim 11 or 12 wherein said integrated circuit surface (12) comprises a diffusion barrier formed on a semiconductor surface, and said diffusion barrier is subsequently patterned together with said interconnect film (14).
Claim 17
Dependent Claim
14 words
A method a claimed in Claim 14 wherein said diffusion barrier comprises titanium nitride.
Claim 18
Independent Claim
32 words
A method as claimed in any of Claims 11 to 15 wherein said top layer (16) transition metal and said conformal layer (22) transition metal are the same type of transition metal.
Claim 19
Independent Claim
28 words
A method as claimed in any of Claims 11 to 15 wherein said top layer (16) transition metal and said conformal layer (22) transition metal are both titanium.
Claim 20
Independent Claim
27 words
A method as claimed in any of Claims 11 to 15 wherein said top layer (16) transition metal is titanium and said conformal layer (22) transition metal.
Claim 21
Independent Claim
29 words
A method as claimed in any of Claims 11 to 15 wherein said top layer (16) transition metal is titanium and said conformal layer (22) transition metal is tungsten.
Claim 22
Independent Claim
162 words
A method of forming on a semiconductor substrate (56) having circuit elements formed therein or thereon, an interconnect for an integrated circuit comprising: forming an aluminium based interconnect film (14) upon but insulated from the semiconductor substrate (56) and the circuit elements previously formed therein or thereon except at selected contact openings formed in the insulating layer, the interconnect film (14) having a thin layer of a first transition metal (16) as a top layer; dry etching the interconnect film (14) into a patterned interconnect member (50) having defined sides for the integrated circuit being fabricated; depositing a conformal layer (22) of a second transition metal over the patterned interconnect member (50) to cover the top and sides of the patterned interconnect; anisotropically dry etching the conformal layer (22) from the top of the patterned interconnect and from areas adjacent the patterned interconnect sides leaving the sides covered by the second transition metal and the top covered by the first transition metal.
Claim 23
Independent Claim
162 words
A method of forming on a semiconductor substrate (56) having circuit elements formed therein or thereon, an interconnect for an integrated circuit comprising: forming an aluminium based interconnect film (14) upon but insulated from the semiconductor substrate (56) and the circuit elements previously formed therein or thereon except at selected contact openings formed in the insulating layer, the interconnect film (14) having a thin layer of a first transition metal (16) as a top layer; dry etching the interconnect film (14) into a patterned interconnect member (50) having defined sides for the integrated circuit being fabricated; depositing a conformal layer (22) of a second transition metal over the patterned interconnect member (50) to cover the top and sides of the patterned interconnect; anisotropically dry etching the conformal layer (22) from the top of the patterned interconnect and from areas adjacent the patterned interconnect sides leaving the sides covered by the second transition metal and the top covered by the first transition metal.
Claim 24
Dependent Claim
34 words
A method as claimed in Claim 20 wherein said interconnect member (50) is spaced from said semiconductor substrate (56) and said circuit elements exposed at said selected contact openings by a diffusion barrier (52).
Claim 25
Dependent Claim
17 words
A method as claimed in Claim 21 wherein said diffusion barrier (52) comprises titanium nitride or tungsten.
Claim 26
Dependent Claim
21 words
A method as claimed in Claim 22 wherein said tungsten diffusion barrier (52) is deposited by a selective chemical vapor deposition.
References Cited (Backward Citations)
No citation records indexed.
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