US5784166A
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US
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Position resolution of an interferometrially controlled moving stage by regression analysis
Assignee: Nikon Corp
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Filing: 1996-04-03
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Granted: 1998-07-21
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Expires: 2016-04-03
Abstract
Abstract A method and apparatus for achieving high position resolution of a moving stage in a lithographic system utilized for the manufacture of semiconductor integrated circuits. A series of values of the stage position are measured using an interferometric system, and a present position of the stage is estimated using regression analysis applied to a selected number of the series of measured values. The resulting predicted position is of higher resolution than a single stage position measurement of the interferometric system.
Inventors
- 👤 Michael R. Sogard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:32
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70216; G03F7/70358; G03F7/70691; G03F7/70716; G03F7/70725; G03F9/00; G03F9/70
Claims Analysis
Total Claims: 66
Claim 1
Independent Claim
63 words
A method of achieving high position resolution in a precision motion system having at least one moving stage, comprising the steps of: measuring a series of positions of said at least one moving stage; and estimating a present position of said at least one moving stage using a selected number of the series of measured positions of said at least one moving stage.
Claim 2
Independent Claim
63 words
A method of achieving high position resolution in a precision motion system having at least one moving stage, comprising the steps of: measuring a series of positions of said at least one moving stage; and estimating a present position of said at least one moving stage using a selected number of the series of measured positions of said at least one moving stage.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein said step of measuring comprises a step of measuring interferometrically.
Claim 4
Dependent Claim
28 words
The method of claim 2, wherein said step of estimating a present position of said at least one moving stage comprises a step of estimating using regression analysis.
Claim 5
Dependent Claim
25 words
The method of claim 3, further comprising the step of controlling the movement of said at least one moving stage with a first servo system.
Claim 6
Dependent Claim
30 words
The method of claim 4, further comprising the step of providing said first servo system a first movement profile to control the movement of said at least one moving stage.
Claim 7
Dependent Claim
13 words
The method of claim 4, wherein said regression analysis is a linear regression.
Claim 8
Dependent Claim
36 words
The method of claim 6, wherein said at least one moving stage is a precision stage, and wherein said regression analysis is performed for time periods shorter than an update time of said first servo system.
Claim 9
Dependent Claim
78 words
The method of claim 5, further comprising the steps of: providing said estimated present position of said at least one moving stage to said first servo system; comparing said estimated present position of said at least one moving stage with a first position defined by said first movement profile; and correcting the movement of said at least one moving stage, whereby a next estimated present position substantially coincides with a second position defined by said first movement profile.
Claim 10
Dependent Claim
65 words
The method of claim 8 wherein said system has at least a second moving stage, and further comprising the steps of: measuring a series of positions of said at least a second moving stage; and estimating a present position of said at least a second moving stage using a selected number of the series of measured positions of said at least a second moving stage.
Claim 11
Dependent Claim
28 words
The method of claim 9, wherein said step of measuring a series of positions of said at least a second moving stage comprises a step of measuring interferometrically.
Claim 12
Dependent Claim
29 words
The method of claim 10, wherein said step of estimating a present position of said at least a second moving stage comprises a step of estimating using regression analysis.
Claim 13
Dependent Claim
26 words
The method of claim 11, further comprising a step of controlling the movement of said at least a second moving stage with a second servo system.
Claim 14
Dependent Claim
92 words
The method of claim 12, further comprising the steps of: providing said second servo system a second movement profile to control the movement of said at least a second moving stage; comparing said estimated present position of said at least a second moving stage with a first position defined by said second movement profile; and correcting the movement of said at least a second moving stage, whereby the estimated next present position of said at least a second moving stage substantially coincides with a second position defined by said second movement profile.
Claim 15
Dependent Claim
32 words
The method of claim 13, wherein said step of providing a second movement profile comprises the step of providing a second movement profile that is a function of said first movement profile.
Claim 16
Dependent Claim
78 words
The method of claim 14, further comprising a step of imaging portions of a mask on said at least one moving stage wherein said at least one moving stage is a mask stage in a lithographic system onto a wafer disposed on said at least a second moving stage wherein said at least a second moving stage is a wafer stage in said lithographic system with a lens system disposed between said mask stage and said wafer stage.
Claim 17
Dependent Claim
18 words
The method of claim 15, further comprising the step of selectively adjusting a magnification of said lens system.
Claim 18
Dependent Claim
54 words
The method of claim 16, wherein said steps of providing first and second movement profiles comprise the steps of providing first and second movement profiles which comprise displacement versus time profiles thereby defining a mask stage velocity and a wafer stage velocity at each point of said first movement profile and second movement profile.
Claim 19
Dependent Claim
46 words
The method of claim 17, wherein said step of providing a second movement profile comprises the step of providing a second movement profile that is a function of said first movement profile, wherein said function is determined by said selectively adjusted magnification of said lens system.
Claim 20
Independent Claim
70 words
An apparatus for achieving high position resolution, comprising: at least one moving stage; a first measurement system located to measure a series of positions of said at least one moving stage; and an estimation system connected to said first measurement system to estimate a present position of said at least one moving stage using a selected number of the series of measured positions of said at least one moving stage.
Claim 21
Independent Claim
70 words
An apparatus for achieving high position resolution, comprising: at least one moving stage; a first measurement system located to measure a series of positions of said at least one moving stage; and an estimation system connected to said first measurement system to estimate a present position of said at least one moving stage using a selected number of the series of measured positions of said at least one moving stage.
Claim 22
Dependent Claim
15 words
The apparatus of claim 19, wherein said first measurement system comprises a first interferometer system.
Claim 23
Dependent Claim
31 words
The apparatus of claim 20, wherein said estimation system is a microprocessor controller wherein said microprocessor controller estimates a present position of said at least one moving stage using regression analysis.
Claim 24
Dependent Claim
35 words
The apparatus of claim 21, further comprising a first control system coupled to said at least one moving stage and to said estimation system to control the movement of said at least one moving stage.
Claim 25
Dependent Claim
37 words
The apparatus of claim 22, wherein said first control system comprises a first servo system wherein said first servo system controls the movement of said at least one moving stage in accordance with a first movement profile.
Claim 26
Dependent Claim
13 words
The apparatus of claim 23, wherein said regression analysis is a linear regression.
Claim 27
Dependent Claim
36 words
The apparatus of claim 24, wherein said at least one moving stage is a precision stage, and wherein said regression analysis is performed for time periods shorter than an update time of said first servo system.
Claim 28
Dependent Claim
68 words
The apparatus of claim 23, wherein said first servo system compares said present predicted position of said at least one moving stage with a first position defined by said first movement profile and corrects the movement of said at least one moving stage, whereby a next estimated present position of said at least one moving stage substantially coincides with a second position defined by said first movement profile.
Claim 29
Dependent Claim
86 words
The apparatus of claim 26, further comprising: at least a second moving stage located space apart from said at least a first moving stage; a second measuring system located adjacent said at least a second moving stage to measure a series of positions of said at least a second moving stage; and wherein said microprocessor controller estimates a present position of said at least a second moving stage using a selected number of the series of measured positions of said at least a second moving stage.
Claim 30
Dependent Claim
15 words
The apparatus of claim 27, wherein said second measurement system comprises a second interferometer system.
Claim 31
Dependent Claim
24 words
The apparatus of claim 28, wherein said microprocessor controller estimates a present position of said at least a second moving stage using regression analysis.
Claim 32
Dependent Claim
38 words
The apparatus of claim 29, further comprising a second control system coupled to said at least a second moving stage and said a second measuring system to control the movement of said at least a second moving stage.
Claim 33
Dependent Claim
38 words
The apparatus of claim 30, wherein said second control system comprises a second servo system wherein said second servo system controls the movement of said at least a second moving stage in accordance with a second movement profile.
Claim 34
Dependent Claim
71 words
The apparatus of claim 31, wherein said second servo system compares said present predicted position of said at least a second moving stage with a first position defined by said second movement profile and corrects the movement of said at least a second moving stage, whereby a next estimated present position of said at least a second moving stage substantially coincides with a second position defined by said second movement profile.
Claim 35
Dependent Claim
36 words
The apparatus of claim 32, wherein: said at least one moving stage is a mask stage in a lithographic system; and said at least a second moving stage is a wafer stage in said lithographic system.
Claim 36
Dependent Claim
18 words
The apparatus of claim 33, wherein said second movement profile is a function of said first second profile.
Claim 37
Dependent Claim
16 words
The apparatus of claim 34, further comprising a lens system disposed adjacent to said wafer stage.
Claim 38
Dependent Claim
13 words
The apparatus of claim 35, wherein said lens system has a selected magnification.
Claim 39
Dependent Claim
19 words
The apparatus of claim 36, wherein said lens system is disposed between said mask stage and said wafer stage.
Claim 40
Dependent Claim
26 words
The apparatus of claim 37, wherein said selected magnification of said lens system determines said function between said first movement profile and said second movement profile.
Claim 41
Dependent Claim
41 words
The apparatus of claim 38, wherein said first movement profile and said second movement profile comprise displacement versus time profiles thereby defining said wafer stage velocity and said mask stage velocity at each point of said first and second movement profiles.
Claim 42
Independent Claim
58 words
An apparatus for achieving high position resolution, comprising: at least one moving stage; means for measuring a series of positions of said at least one moving stage; and means for estimating a present position of said at least one moving stage using a selected number of the series of measured positions of said at least one moving stage.
Claim 43
Independent Claim
58 words
An apparatus for achieving high position resolution, comprising: at least one moving stage; means for measuring a series of positions of said at least one moving stage; and means for estimating a present position of said at least one moving stage using a selected number of the series of measured positions of said at least one moving stage.
Claim 44
Dependent Claim
25 words
The apparatus of claim 40, wherein said means for estimating uses regression analysis to estimate the present position of said at least one moving stage.
Claim 45
Dependent Claim
19 words
The apparatus of claim 41, further comprising means for controlling the movement of said at least one moving stage.
Claim 46
Dependent Claim
27 words
The apparatus of claim 42, wherein said means for controlling controls the movement of said at least one moving stage in accordance with a first movement profile.
Claim 47
Dependent Claim
13 words
The apparatus of claim 42, wherein said regression analysis is a linear regression.
Claim 48
Dependent Claim
43 words
The apparatus of claim 44, wherein said at least one moving stage is a precision stage, said means for controlling includes a servo system, and wherein said regression analysis is performed for time periods shorter than an update time of said servo system.
Claim 49
Dependent Claim
69 words
The apparatus of claim 43, further comprising: means for comparing said estimated present position of said at least one moving stage with a first position defined by said first movement profile; and means for correcting the movement of said at least one moving stage whereby a next estimated present position of said at least one moving stage substantially coincides with a second position defined by said first movement profile.
Claim 50
Dependent Claim
60 words
The apparatus of claim 46, further comprising: at least a second moving stage; means for measuring a series of positions of said at least a second moving stage; and means for estimating a present position of said at least a second stage using a selected number of the series of measured positions of said at least a second moving stage.
Claim 51
Dependent Claim
36 words
The apparatus of claim 47, wherein said means for estimating a present position of said at least a second stage uses regression analysis to estimate said present position of said at least a second moving stage.
Claim 52
Dependent Claim
20 words
The apparatus of claim 48, further comprising means for controlling the movement of said at least a second moving stage.
Claim 53
Dependent Claim
38 words
The apparatus of claim 49, wherein said means for controlling the movement of said at least a second moving stage controls the movement of said at least a second moving stage in accordance with a second movement profile.
Claim 54
Dependent Claim
72 words
The apparatus of claim 50, further comprising: means for comparing said estimated present position of said at least a second moving stage with a first position defined by said second moving profile; and means for correcting the movement of said at least a second moving stage whereby a next estimated present position of said at least a second moving stage substantially coincides with a second position defined by said second movement profile.
Claim 55
Dependent Claim
18 words
The apparatus of claim 51, wherein said first movement profile is a function of said second movement profile.
Claim 56
Dependent Claim
44 words
The apparatus of claim 52, wherein: said means for controlling the movement of said at least one moving stage comprises a first servo system; and said means for controlling the movement of said at least a second moving stage comprises a second servo system.
Claim 57
Dependent Claim
36 words
The apparatus of claim 53, wherein: said at least one moving stage comprises a mask stage in a lithographic system; and said at least a second moving stage comprises a wafer stage in said lithographic system.
Claim 58
Dependent Claim
28 words
The apparatus of claim 54, further comprising means for transferring an image of a mask disposed on said mask stage to a wafer disposed on said wafer stage.
Claim 59
Dependent Claim
18 words
The apparatus of claim 55, wherein said means for transferring comprises a lens system with a selected magnification.
Claim 60
Dependent Claim
12 words
The apparatus of claim 56, wherein said selected magnification determines said function.
Claim 61
Dependent Claim
42 words
The apparatus of claim 57, wherein said first movement profile and said second movement profile comprise displacement versus time profiles thereby defining said wafer stage velocity and said mask stage velocity at each point of said first and second movement profiles respectively.
Claim 62
Dependent Claim
39 words
The apparatus of claim 58, wherein said means for estimating a present position of said at least one moving stage and said means for estimating a present position of said at least a second stage comprises a microprocessor controller.
Claim 63
Dependent Claim
48 words
The apparatus of claim 59, wherein: said means for measuring a series of positions of said at least one moving stage comprises a first interferometer system; and said means for measuring a series of positions of said at least a second moving stage comprises a second interferometer system.
Claim 64
Dependent Claim
47 words
The method of claim 1, wherein the measurement of the series of positions is made at regular time intervals while said at least one moving stage is moving, and wherein said estimate of said present position is made while said at least one moving stage is moving.
Claim 65
Dependent Claim
46 words
The apparatus of claim 19, wherein said first measurement system measures a series of positions at regular time intervals while said at least one moving stage is moving, and wherein said estimation system estimates a present position while said at least one moving stage is moving.
Claim 66
Dependent Claim
62 words
The apparatus of claim 40, wherein said means for measuring a series of positions of said at least one moving stage measures at a regular time interval while said at least one moving stage is moving, and wherein said means for estimating a present position of said at least one moving stage estimates while said at least one moving stage is moving.
References Cited (Backward Citations)
US4546355A
Cited
US5182615A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-07-20 | 2002-01-19 | 2002-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-07-20 | 2006-01-19 | 2006-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-07-20 | 2010-01-19 | 2010-07-21 | $7700.00 | Window Closed / Lapsed |