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US 5,847,812 AGranted
Projection exposure system and method
AssigneeNikon Corporation
InventorsHiroshi Ooki, Masato Shibuya, Kazuya Okamoto, Soichi Owa
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AssigneeNikon Corporation
InventorsHiroshi Ooki, Masato Shibuya, Kazuya Okamoto, Soichi Owa
Estimating the term…
Projection exposure systems and methods are disclosed that achieve higher light intensities and reduce the time required for each exposure in multiple exposures of non-linear resists such as a two-photon-absorption resist. Using spatial redistribution of laser light, an illumination optical system forms an illumination region that illuminates only a portion of the pattern on a mask with spatially coherent light from a light source. The system forms the entire mask pattern on a substrate by repeating a non-linear exposure while moving the illumination region and the mask pattern relative to one another. To exploit temporal redistribution of laser light, an illumination optical system employs a pulsed-oscillation-type laser light source to form a mask pattern while varying the light intensity profile on a mask.
A projection-exposure system, comprising:
In a projection-exposure method in which light from a light source is condensed by an illumination optical system for illuminating a pattern defined by a mask, and a projection optical system is used to form an image of the pattern on a photosensitive substrate coated with a resist possessing photosensitive characteristics such that exposure proceeds in a nonlinear manner with respect to the intensity of light incident on the resist, an improvement comprising:
A method for exposing a photosensitive substrate with a pattern defined by a mask, the method comprising:
Dependencies are inferred from the claim text.