Method for aberration detection and measurement
First Claim
1. A method for detecting and measuring aberrations in an optical system comprising:
- providing a test target with at least one open figure including a multiple component array of phase zones, whereinthe multiple phase zones are resolvable by the optical system and are arranged within the open figure so that their responses to lens aberrations are interrelated and the phase zones respond uniquely to specific aberrations depending on their location within the figure;
placing the test target in an object plane of a projection system;
imaging a photoresist film with the projection system; and
comparing the image in the photoresist film to a reference image without aberrations to detect aberrations in the optical system.
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Abstract
Aberrations in an optical system can be detected and measured using a method comprised of a test target in the object plane of a projection system and imaging a photoresist film with the system. The test target comprises at least one open figure which comprises a multiple component array of phase zones, where the multiple zones are arranged within the open figure so that their response to lens aberration is interrelated and the zones respond uniquely to specific aberrations depending on their location within the figure. The method detects aberration types including coma, spherical, astigmatism, and three-point through the exposure of a photoresist material placed in the image plane of the system and the evaluation of these images.
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Citations
22 Claims
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1. A method for detecting and measuring aberrations in an optical system comprising:
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providing a test target with at least one open figure including a multiple component array of phase zones, wherein the multiple phase zones are resolvable by the optical system and are arranged within the open figure so that their responses to lens aberrations are interrelated and the phase zones respond uniquely to specific aberrations depending on their location within the figure; placing the test target in an object plane of a projection system; imaging a photoresist film with the projection system; and comparing the image in the photoresist film to a reference image without aberrations to detect aberrations in the optical system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method of detecting aberrations of an optical imaging system, comprising the steps of:
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arranging a test object in the object plane of the system; providing a photoresist layer in the image plane of the system; imaging the test object by means of the system and an imaging beam; developing the photoresist layer, and detecting the developed image by means of a scanning detection device having a resolution which is considerably larger than that of the imaging system, characterized in that use is made of a test object which comprises at least one open figure having a phase structure which is within resolution limits of the optical imaging system, wherein the image of this figure is compared to a reference image of known or no aberration in order to determine the type and amount of aberration in the optical imaging system.
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Specification