Dual-domain lateral shearing interferometer
Abstract
The phase-shifting point diffraction interferometer (PS/PDI) was developed to address the problem of at-wavelength metrology of extreme ultraviolet (EUV) optical systems. Although extremely accurate, the fact that the PS/PDI is limited to use with coherent EUV sources, such as undulator radiation, is a drawback for its widespread use. An alternative to the PS/PDI, with relaxed coherence requirements, is lateral shearing interferometry (LSI). The use of a cross-grating, carrier-frequency configuration to characterize a large-field 4.times.-reduction EUV lithography optic is demonstrated. The results obtained are directly compared with PS/PDI measurements. A defocused implementation of the lateral shearing interferometer in which an image-plane filter allows both phase-shifting and Fourier wavefront recovery. The two wavefront recovery methods can be combined in a dual-domain technique providing suppression of noise added by self-interference of high-frequency components in the test-optic wavefront.
- Inventors:
- Issue Date:
- Research Org.:
- Univ. of California, Oakland, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1174776
- Patent Number(s):
- 6707560
- Application Number:
- 09/632,631
- Assignee:
- University Of California, The Regents Of
- Patent Classifications (CPCs):
-
G - PHYSICS G01 - MEASURING G01M - TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES
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:
- 47 OTHER INSTRUMENTATION
Citation Formats
Naulleau, Patrick P., and Goldberg, Kenneth Alan. Dual-domain lateral shearing interferometer. United States: N. p., 2004.
Web.
Naulleau, Patrick P., & Goldberg, Kenneth Alan. Dual-domain lateral shearing interferometer. United States.
Naulleau, Patrick P., and Goldberg, Kenneth Alan. Tue .
"Dual-domain lateral shearing interferometer". United States. https://www.osti.gov/servlets/purl/1174776.
@article{osti_1174776,
title = {Dual-domain lateral shearing interferometer},
author = {Naulleau, Patrick P. and Goldberg, Kenneth Alan},
abstractNote = {The phase-shifting point diffraction interferometer (PS/PDI) was developed to address the problem of at-wavelength metrology of extreme ultraviolet (EUV) optical systems. Although extremely accurate, the fact that the PS/PDI is limited to use with coherent EUV sources, such as undulator radiation, is a drawback for its widespread use. An alternative to the PS/PDI, with relaxed coherence requirements, is lateral shearing interferometry (LSI). The use of a cross-grating, carrier-frequency configuration to characterize a large-field 4.times.-reduction EUV lithography optic is demonstrated. The results obtained are directly compared with PS/PDI measurements. A defocused implementation of the lateral shearing interferometer in which an image-plane filter allows both phase-shifting and Fourier wavefront recovery. The two wavefront recovery methods can be combined in a dual-domain technique providing suppression of noise added by self-interference of high-frequency components in the test-optic wavefront.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {3}
}
Works referenced in this record:
Lateral-shearing interferometer using square prisms for optical testing of aspheric lenses
journal, July 1998
- Kim, Seung-Woo; Cho, Woo-Jong; Kim, Byoung-Chang
- Measurement Science and Technology, Vol. 9, Issue 7