US5738562A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for planar end-point detection during chemical-mechanical polishing
Assignee: Micron Technology Inc
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Filing: 1996-01-24
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Granted: 1998-04-14
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Expires: 2016-01-24
Abstract
Abstract A chemical-mechanical polishing apparatus includes a slurry-wetted polishing pad attached to a substantially planar surface of a platen. A wafer carrier is positioned in close proximity to the platen, and it has a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad. An actuator imparts a translational motion to the platen so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer. A sensor detects a change in the imparted translational motion corresponding to a change in the coefficient of friction between the polishing pad and the opposing side of the semiconductor wafer indicative of a planar end point on the opposing side of the semiconductor wafer. The sensor preferably includes a laser and a laser detector using a laser reflection or laser interferometric method to detect the change in the imparted translational motion. Also, the apparatus preferably includes a controller coupled to the sensor and the actuator to adjust the actuator in response to the sensor detecting a change in the imparted translational motion.
Inventors
- 👤 Trung Tri Doan
- 👤 Gurtej Singh Sandhu
- 👤 Malcolm K. Grief
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:07
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/005; B24B37/013; B24B49/00; B24B49/12
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
171 words
A polishing apparatus comprising: a platen having a substantially planar surface; a polishing pad attached to the platen's substantially planar surface; a wafer carrier positioned in close proximity to the platen, the wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad; an actuator for imparting a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer the imparted motion having a maximum translational distance that changes in magnitude when the coefficient of friction between the wafer and the polishing pad changes; and a sensor for detecting a change in the maximum translational distance in the imparted motion resulting from a change in the coefficient of friction between the polishing pad and the opposing side of the semiconductor wafer indicative of a planar end-point on the opposing side of the semiconductor wafer.
Claim 2
Dependent Claim
171 words
A polishing apparatus comprising: a platen having a substantially planar surface; a polishing pad attached to the platen's substantially planar surface; a wafer carrier positioned in close proximity to the platen, the wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad; an actuator for imparting a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer the imparted motion having a maximum translational distance that changes in magnitude when the coefficient of friction between the wafer and the polishing pad changes; and a sensor for detecting a change in the maximum translational distance in the imparted motion resulting from a change in the coefficient of friction between the polishing pad and the opposing side of the semiconductor wafer indicative of a planar end-point on the opposing side of the semiconductor wafer.
Claim 3
Dependent Claim
33 words
The apparatus of claim 1 further comprising a controller operatively coupled to the sensor and the actuator for adjusting the actuator in response to the sensor detecting a change in the imparted motion.
Claim 4
Dependent Claim
58 words
The apparatus of claim 1 wherein the actuator moves the one of the platen and the wafer carrier to a maximum translational velocity whose magnitude changes when the coefficient of friction changes, wherein the sensor detects a change in the maximum translational velocity in order to detect a planar end-point on the opposing side of the semiconductor wafer.
Claim 5
Dependent Claim
11 words
The apparatus of claim 1 wherein the sensor comprises an interferometer.
Claim 6
Dependent Claim
85 words
The apparatus of claim 1 wherein the sensor comprises: a laser for providing a laser beam incident on the one of the platen and the wafer carrier moved by the actuator; and a laser detector for receiving the laser beam reflected from the one of the platen and the wafer carrier, for detecting a change in the time-of-flight for the laser beam, and for thereby detecting a change in the imparted motion indicative of a planar end-point on the opposing side of the semiconductor wafer.
Claim 7
Dependent Claim
12 words
The apparatus of claim 1 wherein the actuator comprises an electric motor.
Claim 8
Dependent Claim
12 words
The apparatus of claim 1 wherein the actuator comprises a hydraulic device.
Claim 9
Dependent Claim
14 words
The apparatus of claim 1 wherein the motion imparted by the actuator is translational.
Claim 10
Dependent Claim
29 words
The detection device of claim 1 wherein the actuator comprises a constant force actuator repetitively applying a constant force between the platen and the wafer carrier in opposite directions.
Claim 11
Dependent Claim
24 words
The detection device of claim 1 wherein the actuator causes the platen to repetitively move relative to the wafer carrier in a opposite directions.
Claim 12
Dependent Claim
47 words
The detection device of claim 10 wherein the sensor detects a characteristic in the imparted motion by detecting a characteristic of the motion imparted between the platen and the wafer carrier during a least two of the repetitive relative movements and comparing the characteristics to each other.
Claim 13
Dependent Claim
27 words
The detection device of claim 1 wherein the characteristic detected by the sensor is a change in the motion imparted between the platen and the wafer carrier.
Claim 14
Dependent Claim
174 words
A planar end-point detection device for a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to impart a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer, the imparted motion having a maximum translational distance that changes in magnitude when the coefficient of friction between the wafer and the polishing pad changes, the detection device comprising a sensor to detect a change in the maximum translational distance in the imparted motion resulting from a change in the coefficient of friction between the polishing pad and the opposing side of the semiconductor wafer indicative of a planar end-point on the opposing side of the semiconductor wafer.
Claim 15
Dependent Claim
174 words
A planar end-point detection device for a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to impart a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer, the imparted motion having a maximum translational distance that changes in magnitude when the coefficient of friction between the wafer and the polishing pad changes, the detection device comprising a sensor to detect a change in the maximum translational distance in the imparted motion resulting from a change in the coefficient of friction between the polishing pad and the opposing side of the semiconductor wafer indicative of a planar end-point on the opposing side of the semiconductor wafer.
Claim 16
Dependent Claim
52 words
The detection device of claim 13 wherein the actuator moves the platen to a maximum translational velocity whose magnitude changes when the coefficient of friction changes, wherein the sensor detects a change in the maximum translational velocity in order to detect a planar end-point on the opposing side of the semiconductor wafer.
Claim 17
Dependent Claim
12 words
The detection device of claim 13 wherein the sensor comprises an interferometer.
Claim 18
Dependent Claim
82 words
The detection device of claim 13 wherein the sensor comprises: a laser for providing a laser beam incident on the one of the platen and the wafer carrier; and a laser detector for receiving the laser beam reflected from the one of the platen and the wafer carrier, for detecting a change in the time-of-flight for the laser beam, and for thereby detecting a change in the imparted motion indicative of a planar end-point on the opposing side of the semiconductor wafer.
Claim 19
Dependent Claim
15 words
The detection device of claim 13 wherein the motion imparted by the actuator is translational.
Claim 20
Dependent Claim
29 words
The detection device of claim 13 wherein the actuator comprises a constant force actuator repetitively applying a constant force between the platen and the wafer carrier in opposite directions.
Claim 21
Dependent Claim
24 words
The detection device of claim 13 wherein the actuator causes the platen to repetitively move relative to the wafer carrier in a opposite directions.
Claim 22
Dependent Claim
47 words
The detection device of claim 19 wherein the sensor detects a change in the imparted motion by detecting a characteristic of the motion imparted between the platen and the wafer carrier during a least two of the repetitive relative movements and comparing the characteristics to each other.
Claim 23
Dependent Claim
27 words
The detection device of claim 13 wherein the characteristic detected by the sensor is a change in the motion imparted between the platen and the wafer carrier.
Claim 24
Dependent Claim
110 words
A polishing method comprising: positioning a semiconductor wafer against a polishing pad; moving the polishing pad relative to the semiconductor wafer with a maximum translational distance that changes in magnitude when the coefficient of friction between the wafer and the polishing pad changes, the polishing pad being in polishing contact with the semiconductor wafer when the polishing pad moves relative to the wafer; and detecting a change in the maximum translational distance in the movement of the polishing pad relative to the semiconductor wafer resulting form a change in the coefficient of friction between the polishing pad and the semiconductor wafer indicative of a planar end-point on the semiconductor wafer.
Claim 25
Dependent Claim
110 words
A polishing method comprising: positioning a semiconductor wafer against a polishing pad; moving the polishing pad relative to the semiconductor wafer with a maximum translational distance that changes in magnitude when the coefficient of friction between the wafer and the polishing pad changes, the polishing pad being in polishing contact with the semiconductor wafer when the polishing pad moves relative to the wafer; and detecting a change in the maximum translational distance in the movement of the polishing pad relative to the semiconductor wafer resulting form a change in the coefficient of friction between the polishing pad and the semiconductor wafer indicative of a planar end-point on the semiconductor wafer.
Claim 26
Dependent Claim
45 words
The method of claim 22 wherein the polishing pad moves relative to the semiconductor wafer at a maximum translational velocity whose magnitude changes when the coefficient of friction changes, wherein detecting a change in the movement includes detecting a change in the maximum translational velocity.
Claim 27
Dependent Claim
15 words
The method of claim 22 wherein a change in the movement is detected using interferometry.
Claim 28
Dependent Claim
17 words
The method of claim 22 wherein a change in the movement is detected using time-of-flight laser reflection.
Claim 29
Dependent Claim
31 words
The method of claim 22 wherein the step of moving the polishing pad relative to the semiconductor wafer comprises repetitively moving the platen relative to the semiconductor wafer in opposite directions.
Claim 30
Dependent Claim
34 words
The method of claim 26 wherein the step of repetitively moving the polishing pad relative to the semiconductor wafer comprises applying a constant force between the platen and the semiconductor wafer in opposite directions.
Claim 31
Dependent Claim
55 words
The method of claim 26 wherein the step of detecting a characteristic in the movement of the polishing pad relative to the semiconductor wafer comprises detecting a characteristic of the motion imparted between the platen and the wafer carrier during a least two of the repetitive relative movements and comparing the characteristics to each other.
Claim 32
Dependent Claim
38 words
The method of claim 22 wherein the step of detecting a characteristic in the movement of the polishing pad relative to the semiconductor wafer comprises detecting a change in the motion imparted between the platen and the wafer.
Claim 33
Dependent Claim
154 words
A planar end-point detection device in a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to impart a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer, the actuator moving the one of the platen and the wafer carrier by a maximum translational distance having a magnitude which changes when the polishing pad polishes through to a planar end-point on the opposing side of the semiconductor wafer, the detection device comprising a sensor to detect a change in the magnitude of the maximum translational distance.
Claim 34
Dependent Claim
154 words
A planar end-point detection device in a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to impart a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer, the actuator moving the one of the platen and the wafer carrier by a maximum translational distance having a magnitude which changes when the polishing pad polishes through to a planar end-point on the opposing side of the semiconductor wafer, the detection device comprising a sensor to detect a change in the magnitude of the maximum translational distance.
Claim 35
Dependent Claim
12 words
The detection device of claim 30 wherein the sensor comprises an interferometer.
Claim 36
Dependent Claim
73 words
The detection device of claim 30 wherein the sensor comprises: a laser for providing a laser beam incident on the one of the platen and the wafer carrier; and a laser detector for receiving the laser beam reflected from the one of the platen and the wafer carrier, for detecting a change in the time-of-flight for the laser beam, and for thereby detecting a change in the magnitude of the maximum translational distance.
Claim 37
Dependent Claim
29 words
The detection device of claim 30 wherein the actuator comprises a constant force actuator repetitively applying a constant force between the platen and the wafer carrier in opposite directions.
Claim 38
Dependent Claim
154 words
A planar end-point detection device in a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to impart a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer, the actuator moving the one of the platen and the wafer carrier to a maximum translational velocity having a magnitude which changes when the polishing pad polishes through to a planar end-point on the opposing side of the semiconductor wafer, the detection device comprising a sensor to detect a change in the magnitude of the maximum translational velocity.
Claim 39
Dependent Claim
154 words
A planar end-point detection device in a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to impart a motion to one of the platen and the wafer carrier so that the polishing pad moves relative to and in polishing contact with the semiconductor wafer, the actuator moving the one of the platen and the wafer carrier to a maximum translational velocity having a magnitude which changes when the polishing pad polishes through to a planar end-point on the opposing side of the semiconductor wafer, the detection device comprising a sensor to detect a change in the magnitude of the maximum translational velocity.
Claim 40
Dependent Claim
12 words
The detection device of claim 34 wherein the sensor comprises an interferometer.
Claim 41
Dependent Claim
73 words
The detection device of claim 34 wherein the sensor comprises: a laser for providing a laser beam incident on the one of the platen and the wafer carrier; and a laser detector for receiving the laser beam reflected from the one of the platen and the wafer carrier, for detecting a change in the time-of-flight for the laser beam, and for thereby detecting a change in the magnitude of the maximum translational velocity.
Claim 42
Dependent Claim
29 words
The detection device of claim 34 wherein the actuator comprises a constant force actuator repetitively applying a constant force between the platen and the wafer carrier in opposite directions.
Claim 43
Dependent Claim
191 words
A planar end-point detection device in a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to move the platen and the wafer carrier back and forth relative to one another so that the polishing pad repeatedly moves relative to and in polishing contact with the semiconductor wafer, the actuator moving the platen and the wafer carrier relative to one another at a maximum translational velocity and to a maximum translational distance during each back and forth movement, the detection device comprising a sensor for detecting one of the maximum translational distance and the maximum translational velocity during each back and forth movement and for detecting a change in the detected one of the maximum translational distance and maximum translational velocity indicative of the polishing pad polishing through to a planar end-point on the opposing side of the semiconductor wafer.
Claim 44
Dependent Claim
191 words
A planar end-point detection device in a polishing apparatus, the polishing apparatus including a platen having a substantially planar surface, a polishing pad attached to the platen's substantially planar surface, a wafer carrier having a substantially planar surface to which one side of a semiconductor wafer is removably attachable so that an opposing side of the semiconductor wafer is disposed against the polishing pad, and an actuator to move the platen and the wafer carrier back and forth relative to one another so that the polishing pad repeatedly moves relative to and in polishing contact with the semiconductor wafer, the actuator moving the platen and the wafer carrier relative to one another at a maximum translational velocity and to a maximum translational distance during each back and forth movement, the detection device comprising a sensor for detecting one of the maximum translational distance and the maximum translational velocity during each back and forth movement and for detecting a change in the detected one of the maximum translational distance and maximum translational velocity indicative of the polishing pad polishing through to a planar end-point on the opposing side of the semiconductor wafer.
Claim 45
Dependent Claim
12 words
The detection device of claim 38 wherein the sensor comprises an interferometer.
Claim 46
Dependent Claim
88 words
The detection device of claim 38 wherein the sensor comprises: a laser for providing a laser beam incident on one of the platen and the wafer carrier; and a laser detector for receiving the laser beam reflected from the one of the platen and the wafer carrier, for detecting a change in the time-of-flight for the laser beam, and for thereby detecting a change in the detected one of the maximum translational distance and velocity indicative of a planar end-point on the opposing side of the semiconductor wafer.
Claim 47
Dependent Claim
29 words
The detection device of claim 38 wherein the actuator comprises a constant force actuator repetitively applying a constant force between the platen and the wafer carrier in opposite directions.
References Cited (Backward Citations)
US3911562A
Cited
US4702792A
Cited
US4944836A
Cited
US5036015A
Cited
US5069002A
Cited
US5308438A
Cited
US5232875A
Cited
US5486129A
Cited
US5461007A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-04-13 | 2001-10-13 | 2002-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-13 | 2005-10-13 | 2006-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-13 | 2009-10-13 | 2010-04-14 | $7700.00 | Window Closed / Lapsed |