Flood exposure process for dual tone development in lithographic applications
First Claim
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1. A method of patterning a substrate, comprising:
- forming a layer of radiation-sensitive material on a substrate;
performing a patterned exposure of said layer of radiation-sensitive material using a mask having a mask critical dimension to form first radiation-sensitive material portions having a high radiation exposure, second radiation-sensitive material portions having a low radiation exposure, and third radiation-sensitive material portions having an intermediate radiation exposure;
performing a first post-exposure bake following said performing said patterned exposure;
performing positive-tone developing of said layer of radiation-sensitive material to remove said first radiation-sensitive material portions from said substrate;
performing a flood exposure of said layer of radiation-sensitive material;
performing a second post-exposure bake following said performing said flood exposure; and
performing negative-tone developing of said layer of radiation-sensitive material to remove said second radiation-sensitive material portions from said substrate,wherein said third radiation-sensitive material portions remain after performing said positive-tone and negative-tone developing.
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Abstract
A method and system for patterning a substrate using a dual tone development process is described. The method and system comprise a flood exposure of the substrate to improve process latitude for the dual tone development process.
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Citations
14 Claims
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1. A method of patterning a substrate, comprising:
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forming a layer of radiation-sensitive material on a substrate; performing a patterned exposure of said layer of radiation-sensitive material using a mask having a mask critical dimension to form first radiation-sensitive material portions having a high radiation exposure, second radiation-sensitive material portions having a low radiation exposure, and third radiation-sensitive material portions having an intermediate radiation exposure; performing a first post-exposure bake following said performing said patterned exposure; performing positive-tone developing of said layer of radiation-sensitive material to remove said first radiation-sensitive material portions from said substrate; performing a flood exposure of said layer of radiation-sensitive material; performing a second post-exposure bake following said performing said flood exposure; and performing negative-tone developing of said layer of radiation-sensitive material to remove said second radiation-sensitive material portions from said substrate, wherein said third radiation-sensitive material portions remain after performing said positive-tone and negative-tone developing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of patterning a substrate, comprising:
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forming a layer of radiation-sensitive material on a substrate; performing a patterned exposure of said layer of radiation-sensitive material using a mask having a mask critical dimension to form first radiation-sensitive material portions having a first radiation exposure level that is one of high or low exposure and a first critical dimension, second radiation-sensitive material portions having a second radiation exposure level that is the other of high or low exposure and a second critical dimension, and third radiation-sensitive material portions having a third radiation exposure level intermediate the first and second radiation exposure levels and a third critical dimension; performing a first post-exposure bake following said performing said patterned exposure; performing a first development of said layer of radiation-sensitive material to remove said first radiation-sensitive material portions from said substrate; performing a flood exposure of said layer of radiation-sensitive material to further expose said second and third material portions to radiation; performing a second post-exposure bake following said performing said flood exposure, wherein said flood exposure and said second post-exposure bake are effective to adjust a de-protection gradient across said second and third material portions and thereby adjust said second and third critical dimensions; and performing a second development of said layer of radiation-sensitive material to remove said second radiation-sensitive material portions from said substrate, wherein one of said first or second developments is a positive-tone development for removing the respective first or second radiation-sensitive material portions having the high radiation exposure level and the other of said first or second developments is a negative-tone development for removing the respective first or second radiation-sensitive material portions having the low radiation exposure level, and wherein said third radiation-sensitive material portions having said adjusted third critical dimension remain after performing said first and second developments. - View Dependent Claims (13, 14)
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Specification