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Title: Interferometric at-wavelength flare characterization of EUV optical systems

Abstract

The extreme ultraviolet (EUV) phase-shifting point diffraction interferometer (PS/PDI) provides the high-accuracy wavefront characterization critical to the development of EUV lithography systems. Enhancing the implementation of the PS/PDI can significantly extend its spatial-frequency measurement bandwidth. The enhanced PS/PDI is capable of simultaneously characterizing both wavefront and flare. The enhanced technique employs a hybrid spatial/temporal-domain point diffraction interferometer (referred to as the dual-domain PS/PDI) that is capable of suppressing the scattered-reference-light noise that hinders the conventional PS/PDI. Using the dual-domain technique in combination with a flare-measurement-optimized mask and an iterative calculation process for removing flare contribution caused by higher order grating diffraction terms, the enhanced PS/PDI can be used to simultaneously measure both figure and flare in optical systems.

Inventors:
 [1];  [2]
  1. Oakland, CA
  2. Berkeley, CA
Issue Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
OSTI Identifier:
873741
Patent Number(s):
6233056
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
G - PHYSICS G03 - PHOTOGRAPHY G03F - PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
interferometric; at-wavelength; flare; characterization; euv; optical; systems; extreme; ultraviolet; phase-shifting; diffraction; interferometer; pdi; provides; high-accuracy; wavefront; critical; lithography; enhancing; implementation; significantly; extend; spatial-frequency; measurement; bandwidth; enhanced; capable; simultaneously; characterizing; technique; employs; hybrid; spatial; temporal-domain; referred; dual-domain; suppressing; scattered-reference-light; noise; hinders; conventional; combination; flare-measurement-optimized; mask; iterative; calculation; process; removing; contribution; caused; grating; terms; measure; figure; frequency measurement; diffraction interferometer; optical systems; extreme ultraviolet; lithography systems; euv optical; scattered-reference-light noise; hybrid spatial; simultaneously measure; /356/

Citation Formats

Naulleau, Patrick P, and Goldberg, Kenneth Alan. Interferometric at-wavelength flare characterization of EUV optical systems. United States: N. p., 2001. Web.
Naulleau, Patrick P, & Goldberg, Kenneth Alan. Interferometric at-wavelength flare characterization of EUV optical systems. United States.
Naulleau, Patrick P, and Goldberg, Kenneth Alan. Mon . "Interferometric at-wavelength flare characterization of EUV optical systems". United States. https://www.osti.gov/servlets/purl/873741.
@article{osti_873741,
title = {Interferometric at-wavelength flare characterization of EUV optical systems},
author = {Naulleau, Patrick P and Goldberg, Kenneth Alan},
abstractNote = {The extreme ultraviolet (EUV) phase-shifting point diffraction interferometer (PS/PDI) provides the high-accuracy wavefront characterization critical to the development of EUV lithography systems. Enhancing the implementation of the PS/PDI can significantly extend its spatial-frequency measurement bandwidth. The enhanced PS/PDI is capable of simultaneously characterizing both wavefront and flare. The enhanced technique employs a hybrid spatial/temporal-domain point diffraction interferometer (referred to as the dual-domain PS/PDI) that is capable of suppressing the scattered-reference-light noise that hinders the conventional PS/PDI. Using the dual-domain technique in combination with a flare-measurement-optimized mask and an iterative calculation process for removing flare contribution caused by higher order grating diffraction terms, the enhanced PS/PDI can be used to simultaneously measure both figure and flare in optical systems.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {1}
}

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Works referenced in this record:

Phase-shifting point diffraction interferometer
journal, January 1996


Phase-shifting point diffraction interferometer
journal, January 1996


Multichannel phase-shifted interferometer
journal, January 1984


Theory and Application of Point-Diffraction Interferometers
journal, January 1975


Liquid-crystal point-diffraction interferometer
journal, January 1994


Progress towards ╬╗/20 extreme ultraviolet interferometry
journal, November 1995