US5645736A
Expired / Lapsed
US
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Method for polishing a wafer
Assignee: Bell Semiconductor LLC
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Filing: 1995-12-29
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Granted: 1997-07-08
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Expires: 2015-12-29
Abstract
Abstract A method is shown for polishing a workpiece such as a semiconductor wafer. A polishing composition is first formed which includes (1) a polishing media particle; and (2) a film forming binder for suspending the particle and forming a temporary film on an exposed surface of the workpiece, the temporary film being dissolvable in a subsequently applied polishing wash, whereby the polishing media particle is freed to polish the workpiece. The polishing composition is applied to the surface of the semiconductor wafer in a spin coating operation and thereafter cured in a hot plate bake or a furnace operation. In order to polish the workpiece, a polishing wash is applied to either or both of the surface of the workpiece or a polishing pad and thereafter causing the pad to be sufficiently proximate to the surface of the workpiece at a pressure and for a time sufficient to polish and planarize the workpiece.
Inventors
- 👤 Derryl D. J. Allman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:15
CPC Classifications
H; H10; H10P; H10P52/00; H10P95/00; H10P95/06; H10P95/062; B; B24; B24B; B24B37/00; B24B37/04; B24B37/042; B24B37/044; C; C09; C09G; C09G1/00; C09G1/02
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
117 words
A method of polishing or planarizing a surface of a workpiece, the method comprising the steps of: applying a polishing composition to the surface of the workpiece, the polishing composition including a polishing media particle and a film forming binder for suspending the particle and forming a temporary film on the surface of the workpiece, the temporary film being dissolvable in a subsequently applied polishing wash, whereby the polishing media particle is freed to polish the surface of the workpiece; and polishing or planarizing the surface of the workpiece by dissolving the film forming binder, thereby gradually freeing the polishing media particles and allowing the freed particles to abrade the surface of the workpiece to an extent.
Claim 2
Independent Claim
117 words
A method of polishing or planarizing a surface of a workpiece, the method comprising the steps of: applying a polishing composition to the surface of the workpiece, the polishing composition including a polishing media particle and a film forming binder for suspending the particle and forming a temporary film on the surface of the workpiece, the temporary film being dissolvable in a subsequently applied polishing wash, whereby the polishing media particle is freed to polish the surface of the workpiece; and polishing or planarizing the surface of the workpiece by dissolving the film forming binder, thereby gradually freeing the polishing media particles and allowing the freed particles to abrade the surface of the workpiece to an extent.
Claim 3
Dependent Claim
27 words
The method of claim 1, wherein the surface of the workpiece is polished or planarized by mechanically and chemically causing the film forming binder to be dissolved.
Claim 4
Dependent Claim
57 words
The method of claim 2, further comprising the steps of: applying a polishing wash to a selected one of the surface of the workpiece and a polishing pad and then causing the pad to be sufficiently proximate to the surface of the workpiece at a pressure and for a time sufficient to polish and planarize the workpiece.
Claim 5
Dependent Claim
47 words
The method of claim 1, wherein the polishing media particle is selected from the group consisting of: silica, calcium oxide, aluminum oxide, silicon nitride, silicon carbide, cesium oxide, natural and synthetic diamond, tungsten oxide, titanium nitride, titanium oxide, other materials harder than silicon dioxide and combinations thereof.
Claim 6
Dependent Claim
21 words
The method of claim 4, wherein the polishing media particle is a silica particle less than about one micron in size.
Claim 7
Dependent Claim
16 words
The composition of claim 1, wherein the film forming binder is a natural or synthetic polymer.
Claim 8
Dependent Claim
42 words
The method of claim 1, wherein the workpiece is a semiconductor wafer having regions of relatively less and more electronic device integration density, the surface of the wafer having a plurality of steps and gaps between at least some of the steps.
Claim 9
Dependent Claim
58 words
The method of claim 7, wherein the surface of the wafer has a planar level above which no workpiece material is desired and below which there exists electronic components which are desirably defect free, the method further comprising planarizing the surface of the wafer to the planar level without substantially adversely affecting the wafer below the planar level.
Claim 10
Dependent Claim
29 words
The method of claim 1, wherein at least selected regions of the surface of the workpiece are coated with the polishing composition by means of a spin coating operation.
Claim 11
Dependent Claim
26 words
The method of claim 9, further comprising the steps of: curing the spin coated polishing composition by means of a hot plate bake or furnace operation.
Claim 12
Dependent Claim
20 words
The method of claim 10, wherein the polishing wash which is applied to the cured film is an aqueous slurry.
Claim 13
Independent Claim
160 words
A method of formulating a polishing or planarizing composition for polishing or planarizing a surface of a workpiece, the method comprising the steps of: formulating a polishing composition which comprises a curable chemical solution by combining in solution: (a) a polishing media particle having a particle size less than about one micron, present in an amount to define a solids content for the composition; (b) a film forming binder for suspending the particle and forming a temporary film on an exposed surface of the workpiece, the temporary film being dissolvable in subsequently applied polishing wash, whereby the polishing media particle is freed to polish the workpiece; (c) a solvent for suspending the polishing media particle in the film forming binder to facilitate forming the temporary film; (d) a wetting agent to improve the wettability of the composition on the exposed surface of the workpiece; and (e) wherein the polishing media particle solids content is less than about 80% by weight.
Claim 14
Independent Claim
160 words
A method of formulating a polishing or planarizing composition for polishing or planarizing a surface of a workpiece, the method comprising the steps of: formulating a polishing composition which comprises a curable chemical solution by combining in solution: (a) a polishing media particle having a particle size less than about one micron, present in an amount to define a solids content for the composition; (b) a film forming binder for suspending the particle and forming a temporary film on an exposed surface of the workpiece, the temporary film being dissolvable in subsequently applied polishing wash, whereby the polishing media particle is freed to polish the workpiece; (c) a solvent for suspending the polishing media particle in the film forming binder to facilitate forming the temporary film; (d) a wetting agent to improve the wettability of the composition on the exposed surface of the workpiece; and (e) wherein the polishing media particle solids content is less than about 80% by weight.
Claim 15
Independent Claim
191 words
A method of polishing or planarizing a surface of a workpiece, the method comprising the steps of: forming a polishing composition comprising: (a) a polishing media particle having a particle size less than about one micron, present in an amount to define a solids content for the composition; (b) a film forming binder for suspending the particle and forming a temporary film on an exposed surface of the workpiece, the temporary film being dissolvable in subsequently applied polishing wash, whereby the polishing media particle is freed to polish the workpiece; (c) a solvent for suspending the polishing media particle in the film forming binder to facilitate forming the temporary film; (d) a wetting agent to improve the wettability of the composition on the exposed surface of the workpiece; and (e) wherein the polishing media particle solids content is less than about 80% by weight. applying the polishing composition to the surface of the workpiece; and polishing or planarizing the surface of the workpiece by dissolving the film forming binder, thereby gradually freeing the polishing media particles and allowing the freed particles to abrade the surface of the workpiece to an extent.
Claim 16
Independent Claim
191 words
A method of polishing or planarizing a surface of a workpiece, the method comprising the steps of: forming a polishing composition comprising: (a) a polishing media particle having a particle size less than about one micron, present in an amount to define a solids content for the composition; (b) a film forming binder for suspending the particle and forming a temporary film on an exposed surface of the workpiece, the temporary film being dissolvable in subsequently applied polishing wash, whereby the polishing media particle is freed to polish the workpiece; (c) a solvent for suspending the polishing media particle in the film forming binder to facilitate forming the temporary film; (d) a wetting agent to improve the wettability of the composition on the exposed surface of the workpiece; and (e) wherein the polishing media particle solids content is less than about 80% by weight. applying the polishing composition to the surface of the workpiece; and polishing or planarizing the surface of the workpiece by dissolving the film forming binder, thereby gradually freeing the polishing media particles and allowing the freed particles to abrade the surface of the workpiece to an extent.
Claim 17
Dependent Claim
27 words
The method of claim 13, wherein the surface of the workpiece is polished or planarized by mechanically and chemically causing the film forming binder to be dissolved.
Claim 18
Dependent Claim
47 words
The method of claim 11, wherein the polishing media particle is selected from the group consisting of: silica, calcium oxide, aluminum oxide, silicon nitride, silicon carbide, cesium oxide, natural and synthetic diamond, tungsten oxide, titanium nitride, titanium oxide, other materials harder than silicon dioxide and combinations thereof.
Claim 19
Dependent Claim
13 words
The method of claim 15, wherein the film forming binder is a polyorganosiloxane.
Claim 20
Dependent Claim
11 words
The method of claim 16, wherein the solvent is an alcohol.
Claim 21
Dependent Claim
13 words
The method of claim 17, wherein the wetting agent is an organofunctional silane.
Claim 22
Dependent Claim
57 words
The method of claim 18, further comprising the steps of: applying a polishing wash to a selected one of the surface of the workpiece and a polishing pad and then causing the pad to be sufficiently proximate to the surface of the workpiece at a pressure and for a time sufficient to polish and planarize the workpiece.
Claim 23
Dependent Claim
42 words
The method of claim 19, wherein the workpiece is a semiconductor wafer having regions of relatively less and more electronic device integration density, the surface of the wafer having a plurality of steps and gaps between at least some of the steps.
Claim 24
Dependent Claim
58 words
The method of claim 20, wherein the surface of the wafer has a planar level above which no workpiece material is desired and below which there exists electronic components which are desirably defect free, the method further comprising planarizing the surface of the wafer to the planar level without substantially adversely affecting the wafer below the planar level.
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