US5897375A
Expired / Lapsed
US
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Chemical mechanical polishing (CMP) slurry for copper and method of use in integrated circuit manufacture
Assignee: North Star Innovations Inc
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Filing: 1997-10-20
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Granted: 1999-04-27
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Expires: 2017-10-20
Abstract
Abstract A method for chemical mechanical polishing (CMP) a copper layer (22) begins by forming the copper layer (22). The copper layer (22) is then exposed to a slurry (24). The slurry (24) contains an oxidizing agent such as H 2 O 2 , a carboxylate salt such as ammonium citrate, an abrasive slurry such as alumna abrasive, an optional triazole or triazole derivative, and a remaining balance of a solvent such as deionized water. The use of the slurry (24) polishes the copper layer (22) with a high rate of removal whereby pitting and corrosion of the copper layer (22) is reduced and good copper interconnect planarity is achieved. This slurry (24) has good selectivity of copper to oxide, and results in copper devices which have good electrical performance. In addition, disposal of the slurry (24) is not environmentally difficult since the slurry (24) is environmentally sound when compared to other prior art slurries.
Inventors
- 👤 David Watts
- 👤 Rajeev Bajaj
- 👤 Sanjit Das
- 👤 Janos Farkas
- 👤 Chelsea Dang
- 👤 Melissa Freeman
- 👤 Jaime A. Saravia
- 👤 Jason Gomez
- 👤 Lance B. Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:33
CPC Classifications
B; B24; B24B; B24B1/00; C; C23; C23F; C23F3/00; C09; C09G; C09G1/00; C09G1/02; C09K; C09K3/00; C09K3/14; C09K3/1454; C09K3/1463; C09K3/1472
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
42 words
A chemical mechanical polishing slurry comprising: 0.2 wt % to 5 wt % of an oxidizing agent; 0.2 wt % to 20 wt % of a carboxylate salt; 1.0 wt % to 12 wt % of an abrasive slurry; and a solvent.
Claim 2
Dependent Claim
42 words
A chemical mechanical polishing slurry comprising: 0.2 wt % to 5 wt % of an oxidizing agent; 0.2 wt % to 20 wt % of a carboxylate salt; 1.0 wt % to 12 wt % of an abrasive slurry; and a solvent.
Claim 3
Dependent Claim
14 words
The chemical mechanical polishing slurry of claim 1 wherein the solvent is deionized water.
Claim 4
Dependent Claim
14 words
The chemical mechanical polishing slurry of claim 1 wherein the solvent is an alcohol.
Claim 5
Dependent Claim
16 words
The chemical mechanical polishing slurry of claim 1 wherein the carboxylate salt is a citrate salt.
Claim 6
Dependent Claim
14 words
The chemical mechanical polishing slurry of claim 4 wherein citrate salt is ammonium citrate.
Claim 7
Dependent Claim
14 words
The chemical mechanical polishing slurry of claim 4 wherein citrate salt is potassium citrate.
Claim 8
Dependent Claim
18 words
The chemical mechanical polishing slurry of claim 1 wherein 1,2,4-triazole is added to the chemical mechanical polishing slurry.
Claim 9
Dependent Claim
32 words
The chemical mechanical polishing slurry of claim 7 wherein the 1,2,4-triazole is added to the chemical mechanical polishing slurry within a weight percentage range of 0.05 wt % to 2.0 wt %.
Claim 10
Dependent Claim
20 words
The chemical mechanical polishing slurry of claim 1 wherein a triazole derivative is added to the chemical mechanical polishing slurry.
Claim 11
Dependent Claim
33 words
The chemical mechanical polishing slurry of claim 9 wherein the triazole derivative is added to the chemical mechanical polishing slurry within a weight percentage range of 0.05 wt % to 2.0 wt %.
Claim 12
Dependent Claim
20 words
The chemical mechanical polishing slurry of claim 1 wherein the oxidizing agent is hydrogen peroxide (H 2 O 2 ).
Claim 13
Dependent Claim
15 words
The chemical mechanical polishing slurry of claim 1 wherein the abrasive slurry is alumina abrasive.
Claim 14
Dependent Claim
41 words
The chemical mechanical polishing slurry of claim 1 comprising: 1.0 wt % to 1.5 wt % of an oxidizing agent; 0.8 wt % to 1.3 wt % of a carboxylate salt; and 2.0 wt % to 4.0 wt % abrasive slurry.
Claim 15
Dependent Claim
34 words
The chemical mechanical polishing slurry of claim 1 comprising: 1.2 wt % of an oxidizing agent; 1.1 wt % of a carboxylate salt which is a citrate salt; and 3.0 wt % abrasive slurry.
Claim 16
Dependent Claim
29 words
The chemical mechanical polishing slurry of claim 1 wherein the oxidizing agent is hydrogen peroxide, the carboxylate salt is ammonium citrate, and the abrasive slurry is an alumina abrasive.
Claim 17
Dependent Claim
20 words
The chemical mechanical polishing slurry of claim 15 wherein a triazole derivative is added to the chemical mechanical polishing slurry.
Claim 18
Independent Claim
102 words
A method for polishing a cooper layer on an integrated circuit, the method comprising the steps of: forming a dielectric layer having a top surface; forming an opening in the dielectric layer; forming a layer comprising copper within the opening and over the top surface of the dielectric layer; and polishing the layer comprising copper with a polishing slurry comprising an oxidizing agent, a citrate salt, an abrasive slurry, and a solvent, wherein a portion of the layer comprising copper overlying the top surface of the dielectric layer is removed and a portion of the layer comprising copper remains and a opening.
Claim 19
Independent Claim
102 words
A method for polishing a cooper layer on an integrated circuit, the method comprising the steps of: forming a dielectric layer having a top surface; forming an opening in the dielectric layer; forming a layer comprising copper within the opening and over the top surface of the dielectric layer; and polishing the layer comprising copper with a polishing slurry comprising an oxidizing agent, a citrate salt, an abrasive slurry, and a solvent, wherein a portion of the layer comprising copper overlying the top surface of the dielectric layer is removed and a portion of the layer comprising copper remains and a opening.
Claim 20
Dependent Claim
29 words
The method of claim 17 wherein the step of forming the layer comprising copper comprises: forming the layer comprising copper with at least an 80% concentration of copper atoms.
Claim 21
Dependent Claim
24 words
The method of claim 17 wherein the step of forming the layer comprising copper comprises: forming the layer comprising copper via an electroplating process.
Claim 22
Dependent Claim
21 words
The method of claim 17 further comprising: performing an oxide polish process after the step of polishing the layer comprising copper.
Claim 23
Dependent Claim
15 words
The method of claim 17 further comprising: adding a triazole derivative to the polishing slurry.
Claim 24
Dependent Claim
13 words
The method of claim 17 further comprising: adding 1,2,4-triazole to the polishing slurry.
Claim 25
Dependent Claim
44 words
The method of claim 17 wherein the polishing slurry comprises: 1.0 wt % to 1.5 wt % of the oxidizing agent; 0.8 wt % to 1.3 wt % of the citrate salt; and 2.0 wt % to 4.0 wt % of the abrasive slurry.
Claim 26
Dependent Claim
10 words
The method of claim 17 wherein the polishing slurry comprises:
Claim 27
Dependent Claim
27 words
2 wt % of the oxidizing agent; 1.1 wt % of the citrate salt which is a citrate salt; and 3.0 wt % of the abrasive slurry.
Claim 28
Dependent Claim
27 words
2 wt % of the oxidizing agent; 1.1 wt % of the citrate salt which is a citrate salt; and 3.0 wt % of the abrasive slurry.
Claim 29
Dependent Claim
11 words
The method of claim 17 wherein citrate salt is ammonium citrate.
Claim 30
Dependent Claim
11 words
The method of claim 17 wherein citrate salt is potassium citrate.
Claim 31
Dependent Claim
12 words
The method of claim 17 wherein the oxidizing agent is hydrogen peroxide.
Claim 32
Dependent Claim
26 words
The method of claim 17 wherein the oxidizing agent is hydrogen peroxide, the citrate salt is ammonium citrate, and the abrasive slurry is an aluminum abrasive.
Claim 33
Dependent Claim
15 words
The method of claim 28 wherein a triazole derivative is added to the polishing slurry.
Claim 34
Independent Claim
171 words
The method for polishing a copper layer on an integrated circuit, the method comprising the steps of: forming a first dielectric layer; forming an etch stop layer over the first dielectric layer; forming a second dielectric layer over the etch stop layer wherein the second dielectric layer has a top surface; forming a via through the first dielectric layer; forming an interconnect trench through the second dielectric layer wherein the via underlies the interconnect trench; forming a barrier layer within the interconnect trench and the via; forming a layer comprising copper within the interconnect trench, within the via, over the top surface of the second dielectric layer, and over the barrier layer; and polishing the layer comprising copper with a slurry comprising an oxidizing agent, a citrate salt, an abrasive slurry, a triazole derivative, and a solvent, a portion of the layer comprising copper remains in the via and the interconnect trench while a portion of the layer comprising copper overlying the top surface of the second dielectric layer is removed.
Claim 35
Independent Claim
171 words
The method for polishing a copper layer on an integrated circuit, the method comprising the steps of: forming a first dielectric layer; forming an etch stop layer over the first dielectric layer; forming a second dielectric layer over the etch stop layer wherein the second dielectric layer has a top surface; forming a via through the first dielectric layer; forming an interconnect trench through the second dielectric layer wherein the via underlies the interconnect trench; forming a barrier layer within the interconnect trench and the via; forming a layer comprising copper within the interconnect trench, within the via, over the top surface of the second dielectric layer, and over the barrier layer; and polishing the layer comprising copper with a slurry comprising an oxidizing agent, a citrate salt, an abrasive slurry, a triazole derivative, and a solvent, a portion of the layer comprising copper remains in the via and the interconnect trench while a portion of the layer comprising copper overlying the top surface of the second dielectric layer is removed.
Claim 36
Dependent Claim
50 words
The method of claim 30 wherein the slurry comprises: 1.0 wt % to 1.5 wt % of the oxidizing agent; 0.8 wt % to 1.3 wt % of the citrate salt; 2.0 wt % to 4.0 wt % of the abrasive slurry; and 0.5% to 2.0% of the triazole derivative.
Claim 37
Dependent Claim
31 words
The method of claim 30 wherein the oxidizing agent is hydrogen peroxide, the citrate salt is ammonium citrate, the abrasive slurry is an alumina abrasive, and the triazole derivative is 1,2,4-triazole.
References Cited (Backward Citations)
US4954142A
Cited
US5084071A
Cited
US4959113A
Cited
US4959113C1
Cited
US5139571A
Cited
US5225034A
Cited
US5391258A
Cited
US5527423A
Cited
US5614444A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-04-26 | 2002-10-26 | 2003-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-04-26 | 2006-10-26 | 2007-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-04-26 | 2010-10-26 | 2011-04-27 | $7700.00 | Window Closed / Lapsed |