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Title: EUV Focus Sensor: Design and Modeling

Abstract

We describe performance modeling and design optimization of a prototype EUV focus sensor (FS) designed for use with existing 0.3-NA EUV projection-lithography tools. At 0.3-NA and 13.5-nm wavelength, the depth of focus shrinks to 150 nm increasing the importance of high-sensitivity focal-plane detection tools. The FS is a free-standing Ni grating structure that works in concert with a simple mask pattern of regular lines and spaces at constant pitch. The FS pitch matches that of the image-plane aerial-image intensity: it transmits the light with high efficiency when the grating is aligned with the aerial image laterally and longitudinally. Using a single-element photodetector, to detect the transmitted flux, the FS is scanned laterally and longitudinally so the plane of peak aerial-image contrast can be found. The design under consideration has a fixed image-plane pitch of 80-nm, with aperture widths of 12-40-nm (1-3 wavelengths), and aspect ratios of 2-8. TEMPEST-3D is used to model the light transmission. Careful attention is paid to the annular, partially coherent, unpolarized illumination and to the annular pupil of the Micro-Exposure Tool (MET) optics for which the FS is designed. The system design balances the opposing needs of high sensitivity and high throughput optimizing the signal-to-noise ratiomore » in the measured intensity contrast.« less

Authors:
; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. Office of Basic EnergySciences
OSTI Identifier:
889263
Report Number(s):
LBNL-61234
R&D Project: 509201; BnR: KC0202030; TRN: US200623%%758
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Proceedings of the SPIE - The International Society for Optical Engineering; Journal Volume: 5751; Related Information: Journal Publication Date: 05/2005
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; APERTURES; ASPECT RATIO; DESIGN; DETECTION; EFFICIENCY; ILLUMINANCE; LIGHT TRANSMISSION; OPTICS; OPTIMIZATION; PERFORMANCE; SENSITIVITY; SIGNAL-TO-NOISE RATIO; SIMULATION; WAVELENGTHS

Citation Formats

Goldberg, Kenneth A., Teyssier, Maureen E., and Liddle, J. Alexander. EUV Focus Sensor: Design and Modeling. United States: N. p., 2005. Web.
Goldberg, Kenneth A., Teyssier, Maureen E., & Liddle, J. Alexander. EUV Focus Sensor: Design and Modeling. United States.
Goldberg, Kenneth A., Teyssier, Maureen E., and Liddle, J. Alexander. Sun . "EUV Focus Sensor: Design and Modeling". United States. https://www.osti.gov/servlets/purl/889263.
@article{osti_889263,
title = {EUV Focus Sensor: Design and Modeling},
author = {Goldberg, Kenneth A. and Teyssier, Maureen E. and Liddle, J. Alexander},
abstractNote = {We describe performance modeling and design optimization of a prototype EUV focus sensor (FS) designed for use with existing 0.3-NA EUV projection-lithography tools. At 0.3-NA and 13.5-nm wavelength, the depth of focus shrinks to 150 nm increasing the importance of high-sensitivity focal-plane detection tools. The FS is a free-standing Ni grating structure that works in concert with a simple mask pattern of regular lines and spaces at constant pitch. The FS pitch matches that of the image-plane aerial-image intensity: it transmits the light with high efficiency when the grating is aligned with the aerial image laterally and longitudinally. Using a single-element photodetector, to detect the transmitted flux, the FS is scanned laterally and longitudinally so the plane of peak aerial-image contrast can be found. The design under consideration has a fixed image-plane pitch of 80-nm, with aperture widths of 12-40-nm (1-3 wavelengths), and aspect ratios of 2-8. TEMPEST-3D is used to model the light transmission. Careful attention is paid to the annular, partially coherent, unpolarized illumination and to the annular pupil of the Micro-Exposure Tool (MET) optics for which the FS is designed. The system design balances the opposing needs of high sensitivity and high throughput optimizing the signal-to-noise ratio in the measured intensity contrast.},
doi = {},
journal = {Proceedings of the SPIE - The International Society for Optical Engineering},
number = ,
volume = 5751,
place = {United States},
year = {Sun May 01 00:00:00 EDT 2005},
month = {Sun May 01 00:00:00 EDT 2005}
}