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US 8,568,964 B2Granted
Flood exposure process for dual tone development in lithographic applications
AssigneeTokyo Electron Limited
InventorsCarlos A. Fonseca, Mark Somervell, Steven Scheer, Wallace P. Printz
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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.
Claims14
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.
6 more elements
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 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.
7 more elements
Dependencies are inferred from the claim text.