US6430022B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling chucking force in an electrostatic
Assignee: Applied Materials Inc
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Filing: 1999-04-19
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Granted: 2002-08-06
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Expires: 2019-04-19
Abstract
Abstract A method and apparatus for use with an electrostatic chuck is described, which incorporates a capacitance measurement circuit for monitoring the capacitance between a wafer substrate and an electrode, or between a plurality of electrodes of the chuck. The capacitance measurement is used for continuous closed-loop control of the chuck operation, in which the voltage applied to the chuck is adjusted according to the measured capacitance.
Inventors
- 👤 Karl F. Leeser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:27
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/70; H10P72/72; H10P72/722; Y; Y10; Y10T; Y10T279/00; Y10T279/23
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
77 words
Apparatus for controlling an electrostatic chuck comprising: an electrostatic chuck having at least one electrode; and a capacitance measuring circuit coupled to one electrode of said electrostatic chuck that provides continuous closed-loop control of a measured capacitance value, and wherein a retention force, produced by the electrostatic chuck in response to the measured capacitance value, is dynamically controlled by maintaining a constant capacitance value as between the electrostatic chuck and a wafer disposed on the electrostatic chuck.
Claim 2
Dependent Claim
77 words
Apparatus for controlling an electrostatic chuck comprising: an electrostatic chuck having at least one electrode; and a capacitance measuring circuit coupled to one electrode of said electrostatic chuck that provides continuous closed-loop control of a measured capacitance value, and wherein a retention force, produced by the electrostatic chuck in response to the measured capacitance value, is dynamically controlled by maintaining a constant capacitance value as between the electrostatic chuck and a wafer disposed on the electrostatic chuck.
Claim 3
Dependent Claim
19 words
The apparatus of claim 1 wherein said capacitance measuring circuit is coupled between two electrodes of said electrostatic chuck.
Claim 4
Dependent Claim
28 words
The apparatus of claim 2 wherein a first of the two electrodes has a propeller-shaped plan form and a second of the two electrodes circumscribes the first electrode.
Claim 5
Dependent Claim
29 words
The apparatus of claim 1 wherein said capacitance measuring circuit is adapted for coupling between one electrode of said electrostatic chuck and a wafer disposed upon said electrostatic chuck.
Claim 6
Dependent Claim
40 words
The apparatus of claim 1 further comprising: a contact member adapted to be electrically connected to a wafer disposed upon said electrostatic chuck wherein said capacitance measuring circuit is coupled between one electrode of said chuck and said contact member.
Claim 7
Dependent Claim
42 words
The apparatus of claim 1 further comprises: a voltage control circuit for applying a voltage to at least one electrode of said electrostatic chuck; and said capacitance measuring circuit has an output signal connected as an input to said voltage control circuit.
Claim 8
Dependent Claim
25 words
The apparatus of claim 1 wherein said capacitance measuring circuit is coupled to said at least one electrode which is embedded within said electrostatic chuck.
Claim 9
Dependent Claim
22 words
The apparatus of claim 1 wherein said capacitance measuring circuit is coupled between at least two electrodes embedded within said electrostatic chuck.
Claim 10
Dependent Claim
34 words
The apparatus of claim 1 wherein said capacitance measuring circuit comprises: an oscillator that produces a frequency of oscillation that represents a capacitance value; and a frequency to voltage converter coupled to said oscillator.
Claim 11
Dependent Claim
34 words
The apparatus of claim 7 , wherein at least one other electrode is disposed upon said electrostatic chuck and said electrode is adapted to electrically connect to a wafer resting upon said electrostatic chuck.
Claim 12
Dependent Claim
29 words
The apparatus of claim 10 , wherein said capacitance measuring circuit is coupled between one of said embedded electrodes and one of said electrodes disposed upon said electrostatic chuck.
Claim 13
Dependent Claim
37 words
The apparatus of claim 1 further comprising: an actuator coupled to the electrostatic chuck; an actuator controller, coupled to the actuator, for causing the actuator to move the electrostatic chuck in response to said measured capacitance value.
Claim 14
Dependent Claim
63 words
Apparatus for controlling the force between a wafer and an electrostatic chuck comprising: an electrostatic chuck having at least one electrode; and means for dynamically controlling a retention force produced by the electrostatic chuck in response to measuring a capacitance value, said means for dynamically controlling the retention force by maintaining a constant capacitance value as between the electrostatic chuck and the wafer.
Claim 15
Dependent Claim
63 words
Apparatus for controlling the force between a wafer and an electrostatic chuck comprising: an electrostatic chuck having at least one electrode; and means for dynamically controlling a retention force produced by the electrostatic chuck in response to measuring a capacitance value, said means for dynamically controlling the retention force by maintaining a constant capacitance value as between the electrostatic chuck and the wafer.
Claim 16
Dependent Claim
32 words
Apparatus for electrostatically retaining a substrate comprising: an outer circular electrode defining a central cutout having a propeller shape; and an inner electrode located within said cutout and having a propeller shape.
Claim 17
Dependent Claim
32 words
Apparatus for electrostatically retaining a substrate comprising: an outer circular electrode defining a central cutout having a propeller shape; and an inner electrode located within said cutout and having a propeller shape.
Claim 18
Dependent Claim
13 words
The apparatus of claim 14 wherein the inner and outer electrodes are coplanar.
Claim 19
Dependent Claim
16 words
The apparatus of claim 15 wherein the inner electrode is spaced apart from the outer electrode.
Claim 20
Independent Claim
79 words
A method of dynamically controlling a retention force between a wafer and an electrostatic chuck comprising the steps of: measuring a capacitance value representing the retention force; controlling, in a continuous closed-loop in response to the capacitance value, a chucking voltage that is applied to the electrostatic chuck to dynamically optimize the retention force while the wafer is being processed by maintaining a constant capacitance value as between the electrostatic chuck and the wafer disposed on the electrostatic chuck.
Claim 21
Independent Claim
79 words
A method of dynamically controlling a retention force between a wafer and an electrostatic chuck comprising the steps of: measuring a capacitance value representing the retention force; controlling, in a continuous closed-loop in response to the capacitance value, a chucking voltage that is applied to the electrostatic chuck to dynamically optimize the retention force while the wafer is being processed by maintaining a constant capacitance value as between the electrostatic chuck and the wafer disposed on the electrostatic chuck.
Claim 22
Dependent Claim
23 words
The method of claim 17 further comprising: measuring a capacitance value to determine if the wafer is positioned properly upon the electrostatic chuck.
Claim 23
Dependent Claim
23 words
The method of claim 17 further comprising: measuring a capacitance value to determine if the wafer is retained properly by the electrostatic chuck.
Claim 24
Dependent Claim
27 words
The method of claim 17 further comprising: measuring a capacitance value to determine if the wafer is dechucked properly by the electrostatic chuck after processing is complete.
Claim 25
Dependent Claim
24 words
The method of claim 17 wherein the capacitance value is represented by an oscillatory signal that changes frequency in response to changes in capacitance.
Claim 26
Dependent Claim
21 words
The method of claim 17 wherein the capacitance value is measured between a pair of electrodes embedded within the electrostatic chuck.
Claim 27
Independent Claim
62 words
A method of dynamically controlling the angular position of a wafer support chuck comprising the steps of: positioning a wafer above a surface of a wafer support chuck having a pair of electrodes; measuring the capacitance between the pair of electrodes; and moving the angular position of said surface of the wafer support chuck until a particular value of capacitance is measured.
Claim 28
Independent Claim
62 words
A method of dynamically controlling the angular position of a wafer support chuck comprising the steps of: positioning a wafer above a surface of a wafer support chuck having a pair of electrodes; measuring the capacitance between the pair of electrodes; and moving the angular position of said surface of the wafer support chuck until a particular value of capacitance is measured.
Claim 29
Dependent Claim
26 words
The method of claim 23 wherein the particular value of capacitance represents that the surface of the wafer support chuck and the wafer are substantially parallel.
Claim 30
Dependent Claim
36 words
Apparatus for electrostatically retaining a substrate comprising: an outer circular electrode defining a central cutout having at least a three-lobe shape; and an inner electrode located within said cutout and having at least a three-lobe shape.
Claim 31
Dependent Claim
36 words
Apparatus for electrostatically retaining a substrate comprising: an outer circular electrode defining a central cutout having at least a three-lobe shape; and an inner electrode located within said cutout and having at least a three-lobe shape.
Claim 32
Dependent Claim
13 words
The apparatus of claim 25 wherein the inner and outer electrodes are coplanar.
Claim 33
Dependent Claim
16 words
The apparatus of claim 25 wherein the inner electrode is spaced apart from the outer electrode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-08-05 | 2006-02-04 | 2006-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-08-05 | 2010-02-04 | 2010-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-08-05 | 2014-02-04 | 2014-08-06 | $7700.00 | Window Closed / Lapsed |