US5340370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slurries for chemical mechanical polishing
Assignee: Micron Technology Inc
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Filing: 1993-11-03
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Granted: 1994-08-23
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Expires: 2013-11-03
Abstract
Abstract Novel slurries for the chemical mechanical polishing of thin films used in integrated circuit manufacturing. A tungsten slurry of the present invention comprises an oxidizing agent, such as potassium ferricyanide, an abrasive such as silica, and has a pH between two and four. The tungsten slurry of the present invention can be used in a chemical mechanical planarization process to polish back a blanket deposited tungsten film to form plugs or vias. The tungsten slurry can also be used to polish copper, tungsten silicide, and titanium nitride. A second slurry, which is a 9:1 dilution of the tungsten slurry is ideal for chemical mechanical polishing of titanium nitride films. A third slurry of the present invention comprises a fluoride salt, an abrasive such as silica and has a pH≦8. The third slurry can be used to polish titanium films.
Inventors
- 👤 Kenneth C. Cadien
- 👤 Daniel A. Feller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:41
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; C; C09; C09G; C09G1/00; C09G1/02; C09K; C09K3/00; C09K3/14; C09K3/1454; C09K3/1463; H10P; H10P52/00; H10P52/40; H10P52/403; H10W20/062
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
38 words
A slurry for chemically mechanically polishing a thin film used in an integrated circuit comprising: an oxidizing agent for said film; an abrasive; and water; wherein said slurry has a pH greater than two and less than four.
Claim 2
Dependent Claim
38 words
A slurry for chemically mechanically polishing a thin film used in an integrated circuit comprising: an oxidizing agent for said film; an abrasive; and water; wherein said slurry has a pH greater than two and less than four.
Claim 3
Dependent Claim
12 words
The slurry of claim 1 wherein said oxidizing agent is potassium ferricyanide.
Claim 4
Dependent Claim
14 words
The slurry of claim 2 wherein said slurry comprises between 0.01-0.3 molar potassium ferricyanide.
Claim 5
Dependent Claim
14 words
The slurry of claim 2 wherein said slurry comprises approximately 0.1 molar potassium ferricyanide.
Claim 6
Dependent Claim
10 words
The slurry of claim 1 comprising 1-25% silica by weight.
Claim 7
Dependent Claim
14 words
The slurry of claim 5 wherein said slurry comprises approximately 5% silica by weight.
Claim 8
Dependent Claim
16 words
The slurry of claim 1 wherein said pH of said slurry is between 3.4 to 3.6.
Claim 9
Dependent Claim
9 words
The slurry of claim 1 further comprising potassium acetate.
Claim 10
Dependent Claim
36 words
A slurry for chemically mechanically polishing a film selected from the group consisting of tungsten and titanium nitride; potassium ferricyanide; silica; and water; wherein said slurry has a pH greater than two and less than four.
Claim 11
Dependent Claim
36 words
A slurry for chemically mechanically polishing a film selected from the group consisting of tungsten and titanium nitride; potassium ferricyanide; silica; and water; wherein said slurry has a pH greater than two and less than four.
Claim 12
Dependent Claim
19 words
The slurry of claim 9 wherein said film is tungsten and said slurry comprises between 0.01-0.3 molar potassium ferricyanide.
Claim 13
Dependent Claim
19 words
The slurry of claim 9 wherein said film is tungsten and said slurry comprises approximately 0.1 molar potassium ferricyanide.
Claim 14
Dependent Claim
19 words
The slurry of claim 9 wherein said film is tungsten and said slurry comprises approximately 5% silica by weight.
Claim 15
Dependent Claim
17 words
The slurry of claim 9 wherein said film is tungsten and said slurry further comprises acetic acid.
Claim 16
Dependent Claim
17 words
The slurry of claim 9 wherein said film is tungsten and said slurry further comprises potassium acetate.
Claim 17
Dependent Claim
40 words
The slurry of claim 9 wherein said film is tungsten and said slurry comprises approximately 0.1 molar potassium ferricyanide; approximately 5% silica by weight; and water; wherein said slurry has a pH of greater than two and less than four.
Claim 18
Dependent Claim
19 words
The slurry of claim 9 wherein said films titanium nitride and said slurry comprises approximately 0.01 molar potassium ferricyanide.
Claim 19
Dependent Claim
20 words
The slurry of claim 9 wherein said film is titanium nitride and said slurry comprises approximately 0.5% silica by weight.
Claim 20
Dependent Claim
26 words
The slurry of claim 9 wherein said film is titanium nitride and said slurry comprises approximately 0.01 molar potassium ferricyanide and approximately 0.5% silica by weight.
Claim 21
Dependent Claim
18 words
The slurry of claim 9 wherein the film is titanium nitride and said slurry further comprises acetic acid.
Claim 22
Dependent Claim
18 words
The slurry of claim 9 wherein the film is titanium nitride and said slurry further comprises potassium acetate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-08-22 | 1998-02-21 | 1998-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-22 | 2002-02-21 | 2002-08-23 | $3760.00 | Window Closed / Lapsed |
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