US5865666A
Expired / Lapsed
US
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Apparatus and method for polish removing a precise amount of material from a wafer
Assignee: Bell Semiconductor LLC
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Filing: 1997-08-20
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Granted: 1999-02-02
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Expires: 2017-08-20
Abstract
Abstract An apparatus and method are presented for polishing removal of a select amount of material from a surface of a semiconductor wafer. The apparatus includes a polishing pad having a moveable planar polishing surface. The surface of the semiconductor wafer and a surface of at least one sacrificial member are retained against the polishing surface. A measurement system determines an amount of material removed from the surface of the sacrificial member. The measurement system includes a sensor unit for each sacrificial member coupled to a computational device. Each sensor unit is used to determine the amount of material remaining at the surface of the corresponding sacrificial member. The computational device determines the amount of material removed from the surface of each sacrificial member based upon the amount of material remaining at the surface. The amount of material removed from the surface of the sacrificial member corresponds to an amount of material removed from the surface of the semiconductor wafer. The computational device uses a correlation between the material removal rates due to polishing (i.e., polish rates) of the sacrificial member and the material upon the surface of the semiconductor wafer to determine when a desired amount of material has been removed from the surface of the semiconductor wafer.
Inventors
- 👤 Ron J. Nagahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:59
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/005; B24B37/013; B24B49/00
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
67 words
An apparatus for removing film from a wafer, comprising: a polishing pad having a moveable polishing surface for simultaneously receiving both the wafer and a sacrificial member spaced from the wafer; and a measurement system for detecting an amount of material removed from the sacrificial member during polishing of said wafer and said sacrificial member and for correlating said amount to said film removed from the wafer.
Claim 2
Independent Claim
67 words
An apparatus for removing film from a wafer, comprising: a polishing pad having a moveable polishing surface for simultaneously receiving both the wafer and a sacrificial member spaced from the wafer; and a measurement system for detecting an amount of material removed from the sacrificial member during polishing of said wafer and said sacrificial member and for correlating said amount to said film removed from the wafer.
Claim 3
Dependent Claim
76 words
The apparatus as recited in claim 1, wherein the measurement system comprises: a sensor unit, comprising: a transmitter for transmitting a signal; and a receiver for receiving a reflected portion of the signal which conveys information as to the amount of material removed from the sacrificial member; and a computational device for determining the amount of material removed from the sacrificial member based upon an amount of material remaining at the surface of the sacrificial member.
Claim 4
Dependent Claim
29 words
The apparatus as recited in claim 2, further comprising a retainer adapted for slideably retaining the wafer, said retainer comprising a first opening dimensioned to secure the wafer therein.
Claim 5
Dependent Claim
25 words
The apparatus as recited in claim 3, wherein the first opening extends into a first chamber along an axis substantially orthogonal to the polishing surface.
Claim 6
Dependent Claim
31 words
The apparatus as recited in claim 4, wherein the retainer further comprises a second opening extending into a second chamber along an axis spaced from the axis of the first opening.
Claim 7
Dependent Claim
19 words
The apparatus as recited in claim 5, wherein said second opening is adapted for slideably retaining a sacrificial member.
Claim 8
Dependent Claim
85 words
The apparatus as recited in claim 4, wherein the retainer further comprises a wafer carrier positioned within the first chamber and adapted to move axially within the first chamber such that the wafer is moveably interposed between the wafer carrier and the polishing pad, and wherein the first chamber comprises an opening through which a fluid is introduced into the first chamber during use such that the fluid exerts pressure upon the wafer carrier, urging the wafer carrier and the wafer toward the polishing surface.
Claim 9
Dependent Claim
94 words
The apparatus as recited in claim 5, wherein the retainer comprises a disk positioned within the second chamber and adapted to move axially within the second chamber such that the sacrificial member is moveably interposed between the disk and the polishing pad, and wherein the retaining structure comprises an opening extending between the first and second chamber which allows the fluid introduced into the first chamber to also enter the second chamber, and wherein during use the fluid exerts pressure upon the disk, urging the disk and the sacrificial member toward the polishing surface.
Claim 10
Dependent Claim
22 words
The apparatus as recited in claim 8, wherein a surface of the sensor unit forms an upper wall of the second chamber.
Claim 11
Dependent Claim
38 words
The apparatus as recited in claim 3, further comprising a sensor spaced separate from the retainer, wherein the sensor element comprises a sensor chamber open at an underside surface of the sensor chamber to receive the sacrificial member.
Claim 12
Dependent Claim
28 words
The apparatus as recited in claim 10, wherein the sensor chamber is cylindrical, and wherein an axis of the sensor chamber is substantially orthogonal to the polishing surface.
Claim 13
Dependent Claim
83 words
The apparatus as recited in claim 11, wherein the sensor element comprises a disk positioned within the sensor chamber and adapted to move along the axis of the sensor chamber, wherein the sacrificial member is interposed between the disk and the polishing pad, and wherein the sensor chamber comprises an opening through which a fluid is introduced into the sensor chamber during use such that the fluid exerts pressure upon the disk, urging the disk and the sacrificial member toward the polishing surface.
Claim 14
Dependent Claim
22 words
The apparatus as recited in claim 11, wherein a surface of the sensor unit forms an upper wall of the sensor chamber.
Claim 15
Dependent Claim
38 words
The apparatus as recited in claim 9, wherein the polishing pad rotates about a central axis, and wherein the radial distances of the axes of the sensor chamber and the first chamber from the central axis are equal.
Claim 16
Independent Claim
96 words
An apparatus for removing material from a surface of a semiconductor wafer, comprising: a polishing pad having a moveable planar polishing surface; a plurality of sacrificial members; a retaining structure for retaining surfaces of the semiconductor wafer and each of the sacrificial members against the polishing surface of the polishing pad; and a measurement system for determining an amount of material removed from each of the sacrificial members, wherein the average amount of material removed from the surfaces of the sacrificial members corresponds to an amount of material removed from the surface of the semiconductor wafer.
Claim 17
Independent Claim
96 words
An apparatus for removing material from a surface of a semiconductor wafer, comprising: a polishing pad having a moveable planar polishing surface; a plurality of sacrificial members; a retaining structure for retaining surfaces of the semiconductor wafer and each of the sacrificial members against the polishing surface of the polishing pad; and a measurement system for determining an amount of material removed from each of the sacrificial members, wherein the average amount of material removed from the surfaces of the sacrificial members corresponds to an amount of material removed from the surface of the semiconductor wafer.
Claim 18
Dependent Claim
118 words
The apparatus as recited in claim 15, wherein the measurement system comprises: a plurality of sensor units equal in number to the number of sacrificial members, wherein each sensor unit comprises: a transmitter for transmitting a signal; and a receiver for receiving a reflected portion of the signal, wherein the reflected portion of the signal conveys information as to the amount of material remaining at the surface of the corresponding sacrificial member; and a computational device for determining: the amount of material removed at the surface of each sacrificial member based upon the amount of material remaining at the surface of the sacrificial member; and the average amount of material removed from the surfaces of the sacrificial members.
Claim 19
Dependent Claim
33 words
The apparatus as recited in claim 15, wherein the retaining structure rotates about an axis through the center of the semiconductor wafer and orthogonal to the planar polishing surface of the polishing pad.
Claim 20
Independent Claim
163 words
A method of achieving a desired thickness of a layer of a material upon a surface of a semiconductor wafer, comprising: providing an apparatus, comprising: a polishing pad having a moveable planar polishing surface; a retaining structure for retaining the surface of the semiconductor wafer against the polishing surface of the polishing pad; a sacrificial member, wherein a surface of the sacrificial member is retained against the polishing surface of the polishing pad; and a measurement system for determining a change in dimension of the sacrificial member orthogonal to the planar polishing surface of the polishing pad; determining a required change in dimension of the sacrificial member orthogonal to the planar polishing surface of the polishing pad which corresponds to the desired final thickness of the layer upon the surface of the semiconductor wafer; and moving the polishing pad relative to the surfaces of the semiconductor wafer and the sacrificial member until the required change of dimension of the sacrificial member is achieved.
Claim 21
Independent Claim
163 words
A method of achieving a desired thickness of a layer of a material upon a surface of a semiconductor wafer, comprising: providing an apparatus, comprising: a polishing pad having a moveable planar polishing surface; a retaining structure for retaining the surface of the semiconductor wafer against the polishing surface of the polishing pad; a sacrificial member, wherein a surface of the sacrificial member is retained against the polishing surface of the polishing pad; and a measurement system for determining a change in dimension of the sacrificial member orthogonal to the planar polishing surface of the polishing pad; determining a required change in dimension of the sacrificial member orthogonal to the planar polishing surface of the polishing pad which corresponds to the desired final thickness of the layer upon the surface of the semiconductor wafer; and moving the polishing pad relative to the surfaces of the semiconductor wafer and the sacrificial member until the required change of dimension of the sacrificial member is achieved.
Claim 22
Dependent Claim
109 words
The method as recited in claim 18, wherein the determining step comprises: determining the change in thickness of the layer upon the surface of the semiconductor wafer per unit of polishing time; determining the change in dimension of the sacrificial member orthogonal to the planar polishing surface of the polishing pad per unit of polishing time; calculating a relative change value by dividing the change in dimension of the sacrificial member per unit of polishing time by the change in thickness of the layer per unit of polishing time; and multiplying the desired thickness of the layer at the surface of the semiconductor wafer by the relative change value.
References Cited (Backward Citations)
US5191738A
Cited
US5298110A
Cited
US5308438A
Cited
US5499733A
Cited
US5536202A
Cited
US5664989A
Cited
US5672095A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-01 | 2002-08-03 | 2003-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-01 | 2006-08-03 | 2007-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-01 | 2010-08-03 | 2011-02-02 | $7700.00 | Window Closed / Lapsed |