Reticle defect printability verification by resist latent image comparison
First Claim
1. A system for examining a reticle for defect printability comprising:
- a wafer exposure system for transferring one or more die patterns from a reticle to a resist wafer to form latent images which correspond to the one or more die patterns, wherein the wafer exposure system comprises a latent image inspection system for comparing the latent images to one another in order to verify whether the one or more die patterns are defective.
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Accused Products
Abstract
One aspect of the present invention relates to a system and method for detecting defects on a reticle by inspecting latent images printed on a resist wafer by the reticle. The system includes a wafer having a printed photoresist layer formed thereon, a latent image inspection system connected to the wafer exposure system for examining the printed photoresist layer in order to determine whether a reticle employed to print the photoresist layer is defective, and a processor for receiving data from the inspection system in order to verify the presence of defects on the reticle. The method involves printing a first latent image, a second latent image, and a third latent image on a resist wafer using a reticle, and comparing the three latent images to one another to determine whether the reticle is defective. Comparison of the latent images may be facilitated by employing an optical system programmed to perform such comparisons.
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Citations
24 Claims
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1. A system for examining a reticle for defect printability comprising:
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a wafer exposure system for transferring one or more die patterns from a reticle to a resist wafer to form latent images which correspond to the one or more die patterns, wherein the wafer exposure system comprises a latent image inspection system for comparing the latent images to one another in order to verify whether the one or more die patterns are defective. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for examining a reticle for defect printability comprising:
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a wafer exposure system comprising a resist wafer, the resist wafer comprising a photoresist layer formed over a substrate, the photoresist layer having at least a first latent image, at least a second latent image, and at least a third latent image printed therein;
a latent image inspection system operatively connected to the wafer exposure system for examining the printed latent images in order to determine whether a reticle employed to print the latent images is defective, the inspection system comprising a measurement system to facilitate comparing the first, second, and third latent images printed on the photoresist layer; and
a processor for comparing and analyzing data gathered by the inspection system to determine whether at least one of the first, second, and third latent images is defective. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method for examining defect printability of a reticle comprising:
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providing a resist wafer comprising a photoresist layer, the photoresist layer being the uppermost layer;
printing a first latent image, a second latent image, and a third latent image on the photoresist layer using a reticle; and
analyzing the first latent image, the second latent image, and the third latent image with respect to one another to determine whether the reticle is defective. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
directing a beam of light at the first, second, and third latent images printed on the resist wafer;
collecting reflected light data from the first, second, and third latent images; and
comparing the reflected light data from the first, second, and third latent images to determine whether the reticle employed to print the latent images is defective.
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18. The method of claim 16, wherein analyzing the latent images printed on the resist wafer comprises employing an optical system to generate data relating to the appearance of the latent images such that they may be qualitatively compared.
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19. The system of claim 16, wherein analyzing the first, second, and third latent images printed on the resist wafer comprises at least three comparisons of the latent images in order to verify a defect location on the reticle, the three comparisons comprising a first comparison between the first and the second latent images, a second comparison between the second and the third latent images, and a third comparison between the first and the third latent images.
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20. The method of claim 16, further comprising enhancing the contrastability of the resist wafer to facilitate inspection and comparison of the latent images.
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21. The method of claim 20, wherein enhancing the contrastability of the photoresist layer comprises at least one of varying a focal height of the wafer during the printing process, selectively implanting a bleachable dye into at least a portion of the resist wafer, and exposing the printed resist wafer to dye vapors under a controlled, moisture-rich environment.
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22. The method of claim 20, wherein the first, second, and third latent images may each be printed on the resist wafer at various focal heights in order to enhance the contrast between the latent images and non-printed areas on the resist wafer.
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23. The method of claim 20, wherein the first, second, and third latent images may each be printed on the resist wafer at various exposures, the various exposures comprising a nominal exposure, an underexposure and an overexposure.
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24. The method of claim 16, wherein the first latent image, the second latent image, and the third latent image correspond to at least one die pattern on the reticle.
Specification