US6045435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low selectivity chemical mechanical polishing (CMP) process for use on integrated circuit metal interconnects
Assignee: NXP USA Inc
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Filing: 1997-08-04
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Granted: 2000-04-04
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Expires: 2017-08-04
Abstract
Abstract A method for polishing a metal layer (20) containing a combination of wide features (12), low density features (14), and high density features (18), is illustrated. A hydrophilic polish pad (24) having a shore D hardness of greater than 50 is used along with slurry (22) containing silica and an acidic based oxidizer such as oxadic acid in a chemical mechanical polishing (CMP) process. The result is less than 5:1 and preferably 1:1. This low selectivity results in the metal layer (20) being polished to a level below the surface of the surrounding oxide in a timed-controlled polish.
Inventors
- 👤 Rajeev Bajaj
- 👤 Subramoney Iyer
- 👤 Thom Kobayashi
- 👤 Jaime Saravia
- 👤 Mark Fernandes
- 👤 David K. Watts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:45
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/11; B24B37/20; B24B37/24; B24B37/04; B24B37/042; B24B37/26; H; H10; H10P; H10P52/00; H10P52/40; H10P52/403; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/062
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
85 words
A method for polishing a metal layer, the method comprising the steps of: providing a dielectric layer having a top surface; forming dual inlaid openings in the dielectric layer; forming a metal layer over the dielectric layer wherein the metal layer fills the dual inlaid openings; and polishing the metal layer using a slurry comprising both a silica abrasive and oxalic acid solution to form a planarized dual inlaid structure where a polishing pad having a shore d hardness of greater than 50 is used.
Claim 2
Independent Claim
85 words
A method for polishing a metal layer, the method comprising the steps of: providing a dielectric layer having a top surface; forming dual inlaid openings in the dielectric layer; forming a metal layer over the dielectric layer wherein the metal layer fills the dual inlaid openings; and polishing the metal layer using a slurry comprising both a silica abrasive and oxalic acid solution to form a planarized dual inlaid structure where a polishing pad having a shore d hardness of greater than 50 is used.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein the step of polishing comprises: using a polishing pad comprising polyurethane to provide the shore d hardness of greater than 50.
Claim 4
Dependent Claim
27 words
The method of claim 1 wherein the step of forming the metal layer comprises: forming the metal layer comprising aluminum to form an aluminum dual inlaid interconnect.
Claim 5
Dependent Claim
33 words
The method of claim 1 wherein the step of providing a polishing pad comprises: polishing the metal layer and dielectric layer such that a metal:dielectric selectively is less than or equal to 5:1.
Claim 6
Dependent Claim
31 words
The method of claim 4 wherein the step of providing a polishing pad comprises: polishing the metal layer and dielectric layer such that a metal:dielectric selectively is substantially equal to 1:1.
Claim 7
Dependent Claim
62 words
The method of claim 1 wherein the step of patterning the dielectric layer comprises: patterning a first opening having a dimension of greater than 40 microns and forming a second opening having an area less than 1 micron by 1 micron wherein polish-induced dishing for the first and second openings is substantially equal in severity due to a low metal:dielectric selectivity polish.
Claim 8
Independent Claim
109 words
A method for polishing a metal layer, the method comprising the steps of: providing a dielectric layer having a top surface; forming dual inlaid openings in the dielectric layer, a first opening having a first dimension of greater than 40 microns and a second dimension greater than 5 microns, and a second opening having an area less than 1 micron by 1 micron; forming the metal layer over the dielectric layer wherein the metal layer fills the dual inlaid openings; and polishing the metal layer using a slurry, wherein polish-induced dishing for the first and second openings is substantially equal in severity due to a low metal:dielectric selectivity polish.
Claim 9
Independent Claim
109 words
A method for polishing a metal layer, the method comprising the steps of: providing a dielectric layer having a top surface; forming dual inlaid openings in the dielectric layer, a first opening having a first dimension of greater than 40 microns and a second dimension greater than 5 microns, and a second opening having an area less than 1 micron by 1 micron; forming the metal layer over the dielectric layer wherein the metal layer fills the dual inlaid openings; and polishing the metal layer using a slurry, wherein polish-induced dishing for the first and second openings is substantially equal in severity due to a low metal:dielectric selectivity polish.
Claim 10
Dependent Claim
30 words
The method of claim 7 wherein the step of polishing comprises: providing a polishing pad comprising polyurethane wherein a shore D hardness of the polishing pad is greater than 50.
Claim 11
Dependent Claim
27 words
The method of claim 7 wherein the step of forming the metal layer comprises: forming the metal layer comprising aluminum to form an aluminum dual inlaid interconnect.
Claim 12
Dependent Claim
33 words
The method of claim 7 wherein the step of providing a polishing pad comprises: polishing the metal layer and dielectric layer such that the metal:dielectric selectively is less than or equal to 5:1.
Claim 13
Dependent Claim
31 words
The method of claim 10 wherein the step of providing a polishing pad comprises: polishing the metal layer and dielectric layer such that the metal:dielectric selectively is substantially equal to 1:1.
Claim 14
Dependent Claim
22 words
The method of claim 7 wherein the step of polishing comprises: providing a slurry comprising a silica abrasive and oxalic acid solution.
Claim 15
Independent Claim
94 words
A method for polishing a metal layer on a silicon wafer, the method comprising the steps of: providing a dielectric layer having a top surface; forming openings in the dielectric layer to form different regions across the silicon wafer wherein the different regions are of different opening densities; forming a metal layer over the dielectric layer and within the openings; and polishing the metal layer and the top surface of the dielectric layer using a low selectivity etch whereby opening density regions from 1% to 50% are polished with substantially equal amounts of dishing.
Claim 16
Independent Claim
94 words
A method for polishing a metal layer on a silicon wafer, the method comprising the steps of: providing a dielectric layer having a top surface; forming openings in the dielectric layer to form different regions across the silicon wafer wherein the different regions are of different opening densities; forming a metal layer over the dielectric layer and within the openings; and polishing the metal layer and the top surface of the dielectric layer using a low selectivity etch whereby opening density regions from 1% to 50% are polished with substantially equal amounts of dishing.
Claim 17
Dependent Claim
30 words
The method of claim 13 wherein the step of polishing comprises: providing a polishing pad comprising polyurethane wherein a shore D hardness of the polishing pad is greater than 50.
Claim 18
Dependent Claim
27 words
The method of claim 13 wherein the step of forming the metal layer comprises: forming the metal layer comprising aluminum to form an aluminum dual inlaid interconnect.
Claim 19
Dependent Claim
33 words
The method of claim 13 wherein the step of providing a polishing pad comprises: polishing the metal layer and dielectric layer such that a metal:dielectric selectively is less than or equal to 5:1.
Claim 20
Dependent Claim
31 words
The method of claim 16 wherein the step of providing a polishing pad comprises: polishing the metal layer and dielectric layer such that the metal:dielectric selectively is substantially equal to 1:1.
Claim 21
Dependent Claim
22 words
The method of claim 13 wherein the step of polishing comprises: providing a slurry comprising a silica abrasive and oxalic acid solution.
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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) | 2003-04-04 | 2003-10-04 | 2004-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-04-04 | 2007-10-04 | 2008-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-04-04 | 2011-10-04 | 2012-04-04 | $7700.00 | Window Closed / Lapsed |