US5232875A
Expired / Lapsed
US
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Method and apparatus for improving planarity of chemical-mechanical planarization operations
Assignee: Applied Materials Inc
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Filing: 1992-10-15
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Granted: 1993-08-03
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Expires: 2012-10-15
Abstract
Abstract A method and apparatus for improving planarity of chemical mechanical planarization of semiconductor wafers. The wafer is affixed to the planar surface of a wafer carrier. A planar platen, on which is mounted a polishing pad, is moved about in a plane parallel to the pad surface with either an orbital, fixed-direction vibratory, or random-direction vibratory motion. In one embodiment of the invention, pressure between the surface of the wafer to be polished and the moving polishing pad is generated by the force of gravity acting on at least the wafer and the carrier; in another it is provided by a mechanical force applied normal to the wafer surface. The polishing pad is wetted with a slurry having abrasive particles suspended in a liquid which may be chemically reactive with respect to at least one material on the wafer.
Inventors
- 👤 Mark E. Tuttle
- 👤 Trung T. Doan
- 👤 Angus C. Fox
- 👤 Gurtej S. Sandhu
- 👤 Hugh E. Stroupe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:11
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04; B24B37/07; B24B37/10; B24B37/102; H; H10; H10P; H10P50/00; H10P72/00; H10P72/04; H10P72/0402; H10P72/0404; Y; Y10; Y10S; Y10S438/00; Y10S438/959
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
90 words
A chemical mechanical planarization apparatus comprising a platen having a horizontal, planar upper surface; a slurry-wetted, uniformly-thick polishing pad affixed to said upper surface; a wafer carrier having a lower planar surface to which one side of a semiconductor wafer is removably attachable, the other side of said wafer being disposed against said slurry-wetted polishing pad; and means for imparting non-rotational motion to said platen upper surface, said motion being parallel to that upper surface, and also providing every point on that upper surface with identical during same time interval.
Claim 2
Dependent Claim
90 words
A chemical mechanical planarization apparatus comprising a platen having a horizontal, planar upper surface; a slurry-wetted, uniformly-thick polishing pad affixed to said upper surface; a wafer carrier having a lower planar surface to which one side of a semiconductor wafer is removably attachable, the other side of said wafer being disposed against said slurry-wetted polishing pad; and means for imparting non-rotational motion to said platen upper surface, said motion being parallel to that upper surface, and also providing every point on that upper surface with identical during same time interval.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1, wherein said motion imparted to said upper surface is random-directed vibratory motion.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1, wherein said motion imparted to said upper surface is fixed-direction vibratory motion.
Claim 5
Dependent Claim
17 words
The apparatus of claim 1, wherein said motion imparted to said upper surface is ellipsoid orbital motion.
Claim 6
Dependent Claim
22 words
The apparatus of claim 4, wherein the distance between the loci of the ellipse, which defines said ellipsoid orbital motion, is zero.
Claim 7
Dependent Claim
29 words
The apparatus of claim 1, wherein said wafer is pressed against the polishing pad by the effect of gravity on at least the wafer, itself, and the wafer carrier.
Claim 8
Dependent Claim
17 words
The apparatus of claim 1, wherein the wafer is pressed against the polishing pad by mechanical force.
Claim 9
Dependent Claim
38 words
The apparatus of claim 1, which further comprises a uniformly-thick, resilient backing pad which is placed between the wafer and said lower planar surface, said resilient backing pad providing frictional attachment of the wafer to the wafer carrier.
Claim 10
Dependent Claim
46 words
The apparatus of claim 7, wherein the coefficients of friction between the backing pad and the wafer, on one side, and the carrier surface, on the other, are at least 1.5 times that of the coefficient of friction between the wafer and the slurry-wetted polishing pad.
Claim 11
Dependent Claim
13 words
The apparatus of claim 1, wherein said polishing pad has a porous surface.
Claim 12
Dependent Claim
25 words
The apparatus of claim 1, wherein said polishing pad is equipped with perforations which extend from a lower surface thereof to an upper surface thereof.
Claim 13
Dependent Claim
26 words
The apparatus of claim 11, wherein slurry is supplied from a supply to the via a network of channels in the upper surface of the platen.
Claim 14
Dependent Claim
23 words
The apparatus of claim 1, wherein the platen is equipped with a barrier wall which surrounds the polishing pad and retains slurry thereon.
Claim 15
Dependent Claim
25 words
The apparatus of claim 13, wherein said barrier wall prevents the wafer carrier and an attached wafer from wandering beyond the limits of the platen.
Claim 16
Dependent Claim
29 words
The apparatus of claim 14, wherein said wafer carrier is equipped with a resilient bumper, which surrounds the carrier and cushions impacts between the carrier and the barrier wall.
Claim 17
Dependent Claim
25 words
The apparatus of claim 14, wherein said barrier wall is equipped with a resilient cushion, which cushions impacts between the carrier and the barrier wall.
Claim 18
Independent Claim
74 words
A method for performing a chemical-mechanical planarization operation on a wafer having front-side and back-side planar surfaces, said method comprising the step of disposing the front-side surface against an abrasive planar surface, said abrasive planar surface being moved non-rotationally, and in a man every point on said front-side surface experiences both virtually identical pressure against said abrasive planar and identical relative motion, with respect to said abrasive planar surface, during the same time interval.
Claim 19
Independent Claim
74 words
A method for performing a chemical-mechanical planarization operation on a wafer having front-side and back-side planar surfaces, said method comprising the step of disposing the front-side surface against an abrasive planar surface, said abrasive planar surface being moved non-rotationally, and in a man every point on said front-side surface experiences both virtually identical pressure against said abrasive planar and identical relative motion, with respect to said abrasive planar surface, during the same time interval.
Claim 20
Dependent Claim
12 words
The method of claim 17, wherein said motion is random-direction vibratory motion.
Claim 21
Dependent Claim
12 words
The method of claim 17, wherein said motion is fixed-direction vibratory motion.
Claim 22
Dependent Claim
12 words
The method of claim 17, wherein said motion is ellipsoid orbital motion.
Claim 23
Dependent Claim
22 words
The method of claim 20, wherein the distance between the loci of the ellipse, which defines the ellipsoid orbital motion, is zero.
Claim 24
Dependent Claim
25 words
The method of claim 17, wherein said abrasive planar surface comprises a polishing pad wetted with a slurry having abrasive particles suspended in a liquid.
Claim 25
Dependent Claim
23 words
The method of claim 22, wherein said liquid is chemically-reactive with respect to at least one material on the front-side of said wafer.
Claim 26
Dependent Claim
48 words
The method of claim 22, wherein said abrasive planar surface is horizontal, said wafer is attached to a wafer carrier, and the pressure between said front-side surface and said abrasive planar surface is generated by the force of gravity acting on at least said wafer and said carrier.
Claim 27
Dependent Claim
37 words
The method of claim 22, wherein said abrasive planar surface is horizontal, said wafer is attached to a wafer carrier, and the pressure between said front-side surface and said abrasive planar surface is variably and mechanically applied.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-02 | 1997-02-01 | 1997-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-02 | 2001-02-01 | 2001-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-02 | 2005-02-01 | 2005-08-03 | $7700.00 | Window Closed / Lapsed |