Method and apparatus for detecting aberrations in a projection lens utilized for projection optics
First Claim
1. A lens aberration monitor for detecting lens aberrations, said monitor comprising:
- a mask for transferring a lithographic pattern onto a substrate, and a plurality of sub-resolution features disposed on said mask, said plurality of sub-resolution features arranged so as to form a predetermined pattern on said substrate, said predetermined pattern being utilized to detect lens aberrations, wherein none of said plurality of sub-resolution features are individually imaged on said substrate.
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Accused Products
Abstract
A method of detecting aberrations associated with a projection lens utilized in an optical lithography system. The method includes the steps of forming a mask for transferring a lithographic pattern onto a substrate, forming a plurality of non-resolvable features disposed on the mask, where the plurality of non-resolvable features are arranged so as to form a predetermined pattern on the substrate, exposing the mask using an optical exposure tool so as to print the mask on the substrate, and analyzing the position of the predetermined pattern formed on the substrate and the position of the plurality of non-resolvable features disposed on the mask so as to determine if there is an aberration. If the position of the predetermined pattern formed on the substrate differs from an expected position, which is determined from the position of the plurality of non-resolvable features, this shift from the expected position indicates the presence of an aberration.
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Citations
41 Claims
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1. A lens aberration monitor for detecting lens aberrations, said monitor comprising:
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a mask for transferring a lithographic pattern onto a substrate, and a plurality of sub-resolution features disposed on said mask, said plurality of sub-resolution features arranged so as to form a predetermined pattern on said substrate, said predetermined pattern being utilized to detect lens aberrations, wherein none of said plurality of sub-resolution features are individually imaged on said substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of forming a lens aberration monitor for detecting lens aberrations, said method comprising the steps:
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forming a mask for transferring a lithographic pattern onto a substrate, and forming a plurality of sub-resolution features disposed on said mask, said plurality of sub-resolution features arranged so as to form a predetermined pattern on said substrate, said predetermined pattern being utilized to detect lens aberrations, wherein none of said plurality of sub-resolution features are individually imaged on said substrate. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A lens aberration monitor for detecting lens aberrations, said monitor comprising:
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a mask for transferring a lithographic pattern onto a substrate, a plurality of sub-resolution features disposed on said mask, said plurality of sub-resolution features arranged so as to form a predetermined pattern on said substrate, said predetermined pattern being utilized to detect lens aberrations, and a lithographic pattern disposed on said mask, said lithographic corresponding to a device to be formed on said substrates, wherein none of said plurality of sub-resolution features are individually imaged on said substrate.
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22. A method of detecting aberrations associated with a projection lens utilized in an optical lithography system, said method comprising the steps:
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forming a mask for transferring a lithographic pattern onto a substrate, forming a plurality of sub-resolution features disposed on said mask, said plurality of sub-resolution features arranged so as to form a predetermined pattern on said substrate, exposing said mask using an optical exposure tool so as to print said mask on said substrate, and analyzing the position of said predetermined pattern formed on said substrate and the position of said plurality of sub-resolution features disposed on said mask so as to determine if there is an aberration, wherein none of said plurality of sub-resolution features are individually imaged on said substrate. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A device manufacturing method comprising the steps of:
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(a) providing a substrate which is at least partially covered by a layer of radiation-sensitive material;
(b) providing a mask which contains a pattern;
(c) using a projection beam of radiation and an objective lens to project an image of at least part of the mask pattern onto a target area of the layer of radiation-sensitive material, wherein prior to performing step (c), an aberration monitoring step is performed comprising the step of forming a plurality of sub-resolution features on said mask, said plurality of sub-resolution features arranged so as to form a predetermined pattern on said substrate, said predetermined pattern being utilized to detect lens aberrations, and wherein none of said plurality of sub-resolution features are individually imaged on said substrate. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40, 41)
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Specification