Patent US2174998A successfully refreshed from Google Patents.
US4158613A
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Method of forming a metal interconnect structure for integrated circuits
Assignee: Samsung Electronics Co Ltd
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Filing: 1978-12-04
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Granted: 1979-06-19
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Expires: 1998-12-04
Abstract
Abstract A method for forming an aluminum interconnect structure on an integrated circuit chip which method employs the anodization of the aluminum but eliminates the necessity for the formation of a hard anodic barrier on the aluminum. Furthermore, the technique provides a superior "cold via" contact. A layer of tantalum is placed over an aluminum layer which tantalum is patterned to define the desired aluminum interconnect structure. Both the exposed aluminum and the tantalum are anodized to form both the interconnect structure and a thin layer of anodic tantalum which is then removed.
Inventors
- 👤 Marilyn R. Sogo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:25
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/065; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6324; H10P14/66; H10P14/665; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69391
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
111 words
A method of forming an interconnect structure on a semiconductor substrate, said method comprising: depositing an aluminum layer on said substrate; depositing a layer of a refractory metal on said aluminum layer, said refractory metal being selected from the group of tantalum, hafnium and niobium; defining the interconnect structure on said refractory metal with a photoresist pattern; etching the exposed refractory metal to expose portions of said aluminum layer; removing said photoresist pattern; anodizing said exposed aluminum and said exposed refractory metal such that said exposed aluminum layer is completely anodized while only a thin layer of said refractory metal is anodized; and removing the thin layer of anodized refractory metal.
Claim 2
Independent Claim
111 words
A method of forming an interconnect structure on a semiconductor substrate, said method comprising: depositing an aluminum layer on said substrate; depositing a layer of a refractory metal on said aluminum layer, said refractory metal being selected from the group of tantalum, hafnium and niobium; defining the interconnect structure on said refractory metal with a photoresist pattern; etching the exposed refractory metal to expose portions of said aluminum layer; removing said photoresist pattern; anodizing said exposed aluminum and said exposed refractory metal such that said exposed aluminum layer is completely anodized while only a thin layer of said refractory metal is anodized; and removing the thin layer of anodized refractory metal.
Claim 3
Dependent Claim
12 words
The method according to claim 1 wherein: said refractory metal is tantalum.
Claim 4
Dependent Claim
12 words
The method according to claim 1 wherein: said refractory metal is hafnium.
Claim 5
Dependent Claim
12 words
The method according to claim 1 wherein: said refractory metal is niobium.
Claim 6
Dependent Claim
21 words
The method according to claim 1 wherein: the anodization is performed in a solution selected from phosphoric acid and oxalic acid.
Claim 7
Dependent Claim
21 words
The method according to claim 1 wherein: said thin layer of anodized refractory metal is removed by a carbon tetriflouride plasma.
Claim 8
Independent Claim
127 words
A method of forming an interconnect structure on a semiconductor substrate, said method comprising: depositing a dielectric layer on said substrate and opening vias therein; p1 depositing an aluminum layer on said dielectric layer and said vias; depositing a layer of a refractory metal on said aluminum layer, said refractory metal being selected from the group of tantalum, hafnium and niobium; defining the interconnect structure on said refractory metal with a photoresist pattern; etching the exposed refractory metal to expose portions of said aluminum layer; removing said photoresist pattern; anodizing said exposed aluminum and said exposed refractory metal such that said exposed aluminum layer is completely anodized while only a thin layer of said refractory metal is anodized; and removing the thin layer of anodized refractory metal.
Claim 9
Independent Claim
127 words
A method of forming an interconnect structure on a semiconductor substrate, said method comprising: depositing a dielectric layer on said substrate and opening vias therein; p1 depositing an aluminum layer on said dielectric layer and said vias; depositing a layer of a refractory metal on said aluminum layer, said refractory metal being selected from the group of tantalum, hafnium and niobium; defining the interconnect structure on said refractory metal with a photoresist pattern; etching the exposed refractory metal to expose portions of said aluminum layer; removing said photoresist pattern; anodizing said exposed aluminum and said exposed refractory metal such that said exposed aluminum layer is completely anodized while only a thin layer of said refractory metal is anodized; and removing the thin layer of anodized refractory metal.
Claim 10
Dependent Claim
12 words
The method according to claim 7 wherein: said refractory metal is tantalum.
Claim 11
Dependent Claim
12 words
The method according to claim 7 wherein: said refractory metal is hafnium.
Claim 12
Dependent Claim
12 words
The method according to claim 7 wherein: said refractory metal is niobium.
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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) | 1982-06-18 | 1982-12-18 | 1983-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-18 | 1986-12-18 | 1987-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-18 | 1990-12-18 | 1991-06-19 | $7700.00 | Window Closed / Lapsed |