Patent US1296896A successfully refreshed from Google Patents.
US6848975B2
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US
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Electrochemical planarization of metal feature surfaces
Assignee: Rensselaer Polytechnic Institute
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Filing: 2003-04-09
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Granted: 2005-02-01
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Expires: 2023-04-09
Abstract
Abstract One aspect is directed to an improved method for polishing an integrated circuit. According to one aspect, metal features deposited on an integrated circuit are polished using electropolishing techniques. Because electropolishing is used, polishing avoids removal of softer insulating materials of the integrated circuit.
Inventors
- 👤 David J. Duquette
- 👤 Lisa J. Loparco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:59
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/062; B; B23; B23H; B23H5/00; B23H5/06; B23H5/08; C; C25; C25F; C25F3/00; C25F3/02; C25F3/16; H10P; H10P95/00; H10P95/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
129 words
A method for polishing an integrated circuit comprising a dielectric layer upon which are formed a plurality of features, the method comprising acts of: depositing a metallic layer on a surface of a dielectric layer forming at least one of the plurality of features; polishing a surface of the metallic layer, the act of polishing comprising acts of: exposing a surface of the metallic layer to an electrolyte solution of an electrochemical cell; providing a first electrode of the electrochemical cell and having a potential being maintained at a constant voltage in a stable electropolishing region of the electrochemical cell; maintaining a potential of the integrated circuit, forming an anode of the electrochemical cell; and providing a second electrode, the second electrode forming a cathode of the electrochemical cell.
Claim 2
Independent Claim
129 words
A method for polishing an integrated circuit comprising a dielectric layer upon which are formed a plurality of features, the method comprising acts of: depositing a metallic layer on a surface of a dielectric layer forming at least one of the plurality of features; polishing a surface of the metallic layer, the act of polishing comprising acts of: exposing a surface of the metallic layer to an electrolyte solution of an electrochemical cell; providing a first electrode of the electrochemical cell and having a potential being maintained at a constant voltage in a stable electropolishing region of the electrochemical cell; maintaining a potential of the integrated circuit, forming an anode of the electrochemical cell; and providing a second electrode, the second electrode forming a cathode of the electrochemical cell.
Claim 3
Dependent Claim
30 words
The method according to claim 1 , further comprising an act of depositing, prior to depositing the metallic layer, a non-metallic barrier layer on the surface of the dielectric layer.
Claim 4
Dependent Claim
28 words
The method according to claim 1 , further comprising an act of removing a portion of the metallic layer that extends above the surface of the dielectric layer.
Claim 5
Dependent Claim
31 words
The method according to claim 3 , further comprising an act of stopping the act of polishing when the metal extending above the surface of the dielectric layer is substantially removed.
Claim 6
Dependent Claim
35 words
The method according to claim 3 , further comprising an act of stopping the act of polishing when the surface of the metallic layer is located substantially planar to the surface of the dielectric layer.
Claim 7
Dependent Claim
42 words
The method according to claim 1 , wherein the stable electropolishing region is associated with a voltage range, and wherein the method further comprises an act of maintaining the potential of the first electrode proximate to a center of the voltage range.
Claim 8
Dependent Claim
33 words
The method according to claim 1 , wherein the electrolyte solution includes an oxidizing acid, and the method comprises an act of electropolishing the surface of the metallic layer using the oxidizing acid.
Claim 9
Dependent Claim
24 words
The method according to claim 7 , wherein the oxidizing acid includes at least one of a group comprising phosphoric acid and nitric acid.
Claim 10
Dependent Claim
24 words
The method according to claim 7 , wherein the oxidizing acid includes at least one of a group comprising othophophoric acid and pyrophosphoric acid.
Claim 11
Dependent Claim
23 words
The method according to claim 1 , further comprising an act of maintaining electrical contact between the first electrode and the electrolyte solution.
Claim 12
Dependent Claim
34 words
The method according to claim 1 , wherein the metallic layer includes copper, and the act of polishing comprises an act of removing an overburden of copper by electropolishing a surface of the copper.
References Cited (Backward Citations)
US3692639A
Cited
US3703458A
Cited
US3849270A
Cited
US4073708A
Cited
US4238310A
Cited
US4971676A
Cited
US5096550A
Cited
EP0699782A1
Cited
US6294467B1
Cited
US6303014B1
Cited
WO2001088229A1
Cited
WO2002023616A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2008-02-01 | 2008-08-02 | 2009-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-02-01 | 2012-08-02 | 2013-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-02-01 | 2016-08-02 | 2017-02-01 | $7700.00 | Window Closed / Lapsed |