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

Patent ·
OSTI ID:873741
 [1];  [2]
  1. Oakland, CA
  2. Berkeley, CA
+ Show Author Affiliations

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.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
DOE Contract Number:
AC03-76SF00098
Assignee:
Regents of University of California (Oakland, CA)
Patent Number(s):
US 6233056
OSTI ID:
873741
Country of Publication:
United States
Language:
English

References (5)

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 λ/20 extreme ultraviolet interferometry journal November 1995

Similar Records

Phase-shifting point-diffraction interferometry at EUV wavelengths
Technical Report · Tue Apr 01 00:00:00 EST 1997 · OSTI ID:873741
Interferometric at-wavelength flare characterization of extreme ultraviolet optical systems
Journal Article · Mon Nov 01 00:00:00 EST 1999 · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena · OSTI ID:873741
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At-wavelength, system-level flare characterization of extreme-ultraviolet optical systems
Journal Article · Sat Jun 10 00:00:00 EDT 2000 · Applied Optics · OSTI ID:873741
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Related Subjects

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
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