US6646729B2
Expired / Lapsed
US
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Method of measuring aberration in an optical imaging system
Assignee: ASML Netherlands BV
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Filing: 2001-02-21
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Granted: 2003-11-11
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Expires: 2021-02-21
Abstract
Abstract A method of determining aberration of an optical imaging system comprises measuring at least one parameter, such as position of best-focus and/or lateral position, of an image formed by the imaging system. This is repeated for a plurality of different illumination settings of the imaging system, and from these measurements at least one coefficient, representative of aberration of said imaging system, is calculated.
Inventors
- 👤 Hans Van Der Laan
- 👤 Marco H Moers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:28
CPC Classifications
G; G01; G01M; G01M11/00; G01M11/02; G03; G03F; G03F7/00; G03F7/70; G03F7/70483; G03F7/70591; G03F7/706
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
154 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different illumination settings of said radiation system and/or for a plurality of different numerical aperture settings of said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings.
Claim 2
Independent Claim
154 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different illumination settings of said radiation system and/or for a plurality of different numerical aperture settings of said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings.
Claim 3
Dependent Claim
28 words
A method according to claim 1 , wherein said plurality of different illumination settings comprise different settings of pupil filling at a pupil plane in the imaging system.
Claim 4
Dependent Claim
31 words
A method according to claim 1 , wherein said plurality of different illumination settings comprise different illumination modes selected from the group comprising disc-shaped, annular, quadrupolar, dipolar and soft-multipolar illumination modes.
Claim 5
Dependent Claim
27 words
A method according to claim 1 , wherein said plurality of different illumination settings comprises telecentric and non-telecentric illumination settings, or a plurality of non-telecentric illumination settings.
Claim 6
Dependent Claim
22 words
A method according to claim 1 , wherein said at least one parameter is the position of best focus of said image.
Claim 7
Dependent Claim
20 words
A method according to claim 1 , wherein said at least one parameter is the lateral position of said image.
Claim 8
Dependent Claim
45 words
A method according to claim 1 , wherein said plurality of different illumination settings of said radiation system and/or said plurality of different numerical aperture settings of said projection system are selected such that the variation in at least one measured parameter is substantially maximized.
Claim 9
Independent Claim
210 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings, wherein said plurality of different illumination settings of said radiation system and/or of different numerical aperture settings of said projection system are selected such that the variation in said at least one measured parameter resulting from aberration represented by one or more of said coefficients is substantially zero, while the variation in said at least one parameter as a function of a desired coefficient is non-zero.
Claim 10
Independent Claim
210 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings, wherein said plurality of different illumination settings of said radiation system and/or of different numerical aperture settings of said projection system are selected such that the variation in said at least one measured parameter resulting from aberration represented by one or more of said coefficients is substantially zero, while the variation in said at least one parameter as a function of a desired coefficient is non-zero.
Claim 11
Independent Claim
177 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings; and calculating a theoretical variation, for each of said plurality of different illumination settings, of said at least one measured parameter as a function of a small change in said at least one coefficient.
Claim 12
Independent Claim
177 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings; and calculating a theoretical variation, for each of said plurality of different illumination settings, of said at least one measured parameter as a function of a small change in said at least one coefficient.
Claim 13
Independent Claim
165 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings, wherein said at least one coefficient is calculated by multiple regression or a least-square fit of a set of simultaneous equations.
Claim 14
Independent Claim
165 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings, wherein said at least one coefficient is calculated by multiple regression or a least-square fit of a set of simultaneous equations.
Claim 15
Independent Claim
154 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings, wherein said at least one coefficient is a Zernike coefficient.
Claim 16
Independent Claim
154 words
A method of determining aberration of an optical imaging system, comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; and a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; the method comprising: patterning the projection beam with said patterning device; measuring at least one parameter of an image formed by the projection system, for a plurality of different settings of said radiation system and/or said projection system; and calculating at least one coefficient, representative of aberration of said imaging system, on the basis of said at least one parameter measured at said plurality of settings, wherein said at least one coefficient is a Zernike coefficient.
Claim 17
Dependent Claim
203 words
A lithographic projection apparatus for projecting a patterned beam of radiation onto a substrate provided with a radiation-sensitive layer, the apparatus comprising: a radiation system constructed and arranged to provide a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; an illumination setter constructed and arranged to provide a plurality of different illumination settings of said radiation system and/or a plurality of different numerical aperture settings of said projection system, comprising: a measuring device constructed and arranged to measure at least one parameter of a projected image formed by the projection system; a controller constructed and arranged to select a plurality of different illumination settings and/or a plurality of different numerical aperture settings at which said measuring device takes measurements; and a calculator constructed and arranged to calculate at least one coefficient, representative of aberration of said projection and/or radiation system, on a basis of said at least one parameter measured by said measuring device.
Claim 18
Dependent Claim
203 words
A lithographic projection apparatus for projecting a patterned beam of radiation onto a substrate provided with a radiation-sensitive layer, the apparatus comprising: a radiation system constructed and arranged to provide a projection beam of radiation; a support structure constructed and arranged to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; an illumination setter constructed and arranged to provide a plurality of different illumination settings of said radiation system and/or a plurality of different numerical aperture settings of said projection system, comprising: a measuring device constructed and arranged to measure at least one parameter of a projected image formed by the projection system; a controller constructed and arranged to select a plurality of different illumination settings and/or a plurality of different numerical aperture settings at which said measuring device takes measurements; and a calculator constructed and arranged to calculate at least one coefficient, representative of aberration of said projection and/or radiation system, on a basis of said at least one parameter measured by said measuring device.
Claim 19
Dependent Claim
22 words
An apparatus according to claim 12 , wherein the support structure comprises a mask table constructed and arranged to hold a mask.
Claim 20
Dependent Claim
15 words
An apparatus according to claim 12 , wherein the radiation system comprises a radiation source.
Claim 21
Independent Claim
189 words
A method of manufacturing a device using a lithographic projection apparatus, comprising: (a) providing a substrate that is at least partially covered by a layer of radiation-sensitive material; (b) providing a projection beam of radiation using a radiation system; (c) using a patterning device to endow the projection beam with a pattern in its cross-section; (d) using a projection system to project the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material; measuring, prior to (d), at least one parameter of an image formed by the projection system, for a plurality of different illumination settings of said radiation system and/or for a plurality of different numerical aperture settings of said projection system; calculating at least one coefficient, representative of aberration of said projection and/or radiation system, on a basis of said at least one parameter measured at said plurality of different illumination settings of said radiation system and/or said plurality of different numerical aperture settings of said projection system; correcting for said aberration on the basis of said at least one calculated coefficient, to reduce aberration of an image projected by said projection system.
Claim 22
Independent Claim
189 words
A method of manufacturing a device using a lithographic projection apparatus, comprising: (a) providing a substrate that is at least partially covered by a layer of radiation-sensitive material; (b) providing a projection beam of radiation using a radiation system; (c) using a patterning device to endow the projection beam with a pattern in its cross-section; (d) using a projection system to project the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material; measuring, prior to (d), at least one parameter of an image formed by the projection system, for a plurality of different illumination settings of said radiation system and/or for a plurality of different numerical aperture settings of said projection system; calculating at least one coefficient, representative of aberration of said projection and/or radiation system, on a basis of said at least one parameter measured at said plurality of different illumination settings of said radiation system and/or said plurality of different numerical aperture settings of said projection system; correcting for said aberration on the basis of said at least one calculated coefficient, to reduce aberration of an image projected by said projection system.
Claim 23
Dependent Claim
28 words
A method according to claim 15 , wherein said correcting comprises correcting for changes in lateral and/or best-focus position of said image when changing between different illumination settings.
Claim 24
Dependent Claim
11 words
A device manufactured according to the method of claim 15 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2006-11-10 | 2007-05-12 | 2007-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-11-10 | 2011-05-12 | 2011-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-11-10 | 2015-05-12 | 2015-11-11 | $7700.00 | Window Closed / Lapsed |