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US6428940B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Method for pattern generation with improved image quality

Assignee: Micronic Laser Systems AB
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Filing: 1999-03-02
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Granted: 2002-08-06
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Expires: 2019-03-02
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Abstract

Abstract The present invention relates to a method for creating a microlithographic pattern on a workpiece, for increased resolution and image fidelity. The method comprises the steps of: providing a source for emitting electromagnetic radiation, illuminating by said radiation a spatial light modulator (SLM) having several pixels, projecting an image of the modulator on the workpiece, further coordinating the movement of the workpiece, the feeding of the signals to the modulator and the intensity of the radiation, so that said pattern is stitched together from the partial images created by the sequence of partial patterns, where an area of the pattern is exposed at least twice with a change in at least one, and preferably at least two, of the following parameters between the exposures: data driven to the SLM, focus, angular distribution of the illumination at the SLM, pupil filtering, polarisation.

Inventors

  • 👤 Torbjorn Sandstrom

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 14:48
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/70; G03F7/70691; G03F7/70716; G03F7/70725; B; B23; B23K; B23K26/00; B23K26/02; B23K26/03; B23K26/032; B23K26/06; B23K26/064; B23K26/0648; B41; B41J; B41J2/00; B41J2/435; B41J2/465; G02; G02B; G02B26/00; G02B26/08; G02B26/0816; G02B26/0833; G02B26/0841; G02B27/00; G02B27/0025; G02B27/0037; G02B27/0043; G02B27/42; G02B27/4205; G03F7/2022; G03F7/70008; G03F7/70041; G03F7/70216; G03F7/70283; G03F7/70291; G03F7/70383; G03F7/704; G03F7/70425; G03F7/70475; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/3433; G09G3/346; H; H04; H04N; H04N1/00; H04N1/04; H04N1/19; H04N1/195; H04N5/00; H04N5/74; H04N5/7416; H04N5/7458; G09G3/2007; H04N2201/00; H04N2201/04; H04N2201/0402; H04N2201/0414

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 205 words
A method for creating a microlithographic pattern on a workpiece sensitive to radiation, for increased resolution and image fidelity, comprising the steps of: providing a source for emitting electromagnetic radiation in the wavelength range from extreme ultraviolet (EUV) to infrared (IR), illuminating by said radiation a spatial light modulator (SLM) having a multitude of modulating elements (pixels), projecting an image of the modulator on the workpiece, moving said workpiece and/or projection system relative to each other, further reading from an information storage device a digital description of the pattern description a sequence of partial patterns, extracting from the pattern description a sequence of partial patterns, converting said partial patterns to modulator signals, and feeding said signals to the modulator, further coordinating the movement of the workpiece, the feeding of the signals to the modulator and the intensity of the radiation, so that said pattern is stitched together from the partial images created by the sequence of partial patterns, wherein an area of the pattern is exposed at least twice with a change in at least one, and preferably at least two, of the following parameters between the exposures: data driven to the SLM focus angular distribution of the illumination at the SLM pupil filtering polarization.
Claim 2
Independent Claim 205 words
A method for creating a microlithographic pattern on a workpiece sensitive to radiation, for increased resolution and image fidelity, comprising the steps of: providing a source for emitting electromagnetic radiation in the wavelength range from extreme ultraviolet (EUV) to infrared (IR), illuminating by said radiation a spatial light modulator (SLM) having a multitude of modulating elements (pixels), projecting an image of the modulator on the workpiece, moving said workpiece and/or projection system relative to each other, further reading from an information storage device a digital description of the pattern description a sequence of partial patterns, extracting from the pattern description a sequence of partial patterns, converting said partial patterns to modulator signals, and feeding said signals to the modulator, further coordinating the movement of the workpiece, the feeding of the signals to the modulator and the intensity of the radiation, so that said pattern is stitched together from the partial images created by the sequence of partial patterns, wherein an area of the pattern is exposed at least twice with a change in at least one, and preferably at least two, of the following parameters between the exposures: data driven to the SLM focus angular distribution of the illumination at the SLM pupil filtering polarization.
Claim 3
Dependent Claim 49 words
A method according to claim 1 , where one exposure has a higher exposure dose and creates a pattern at the workpiece, and the second exposure has a lower exposure dose, an essentially inverse modulation at the SLM and a pupil filter reducing the optical resolution at the workpiece.
Claim 4
Dependent Claim 26 words
A method according to claim 1 , wherein exposures have essentially the same exposure dose and wherein a directional pupil filter is rotated between the exposures.
Claim 5
Dependent Claim 36 words
A method according to claim 1 , where exposures have essentially the same exposure dose and where the pattern data driven to the SLM has a directional asymmetry and said asymmetry is rotated between the exposures.
Claim 6
Dependent Claim 31 words
A method according to claim 1 , where exposures have essentially the same exposure dose and where the polarization of the light impinging on the workpiece is rotated between the exposures.
Claim 7
Dependent Claim 24 words
A method according to claim 1 , where exposures have essentially the same exposure dose and where the focus is changed between the exposures.
Claim 8
Dependent Claim 65 words
A method according to claim 1 , wherein at least two of the following parameters are changed between the exposures and said two changed parameters having a directional property: data driven to the SLM angular distribution of the illumination at the SLM pupil filtering polarization, and said directional property is rotated between the exposures and the rotation is synchronized between the at least two parameters.
Claim 9
Dependent Claim 16 words
A method according to claim 1 , wherein the pupil filter has a dog bone shape.
Claim 10
Dependent Claim 28 words
A method according to claim 1 , where the pupil filter has an area for attenuating the spatial component of the light corresponding to large features in pattern.
Claim 11
Dependent Claim 17 words
A method according to claim 1 , wherein the pupil filter is a secondary spatial light modulator.
Claim 12
Dependent Claim 25 words
A method according to claim 1 , wherein the angular distribution of the illumination at the primary SLM is controlled by an illumination controlling SLM.
Claim 13
Dependent Claim 14 words
A method according to claim 3 , wherein the directional pupil filter is elliptical.
Claim 14
Dependent Claim 14 words
A method according to claim 3 , wherein the directional pupil filter is rectangular.
Claim 15
Dependent Claim 14 words
A method according to claim 3 , wherein the directional pupil filter is wedge-shaped.

References Cited (Backward Citations)

EP0467076A2 Cited
US5148157A Cited
WO1993009469A1 Cited
US5495279A Cited
US5539567A Cited
US5614990A Cited

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

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