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Title: High reflectance and low stress Mo2C/Be multilayers

Abstract

A material for extreme ultraviolet (EUV) multilayers that will reflect at about 11.3 nm, have a high reflectance, low stress, and high thermal and radiation stability. The material consists of alternating layers of Mo.sub.2 C and Be deposited by DC magnetron sputtering on a substrate, such as silicon. In one example a Mo.sub.2 C/Be multilayer gave 65.2% reflectance at 11.25 nm measured at 5 degrees off normal incidence angle, and consisted of 70 bilayers with a deposition period of 5.78 nm, and was deposited at 0.83 mTorr argon (Ar) sputtering pressure, with the first and last layers being Be. The stress of the multilayer is tensile and only +88 MPa, compared to +330 MPa of a Mo/Be multilayers of the same thickness. The Mo.sub.2 C/Be multilayer was capped with carbon which produced an increase in reflectivity of about 7% over a similar multilayer with no carbon capping material, thus raising the reflectivity from 58.3% to over 65%. The multilayers were formed using either Mo.sub.2 C or Be as the first and last layers, and initial testing has shown the formation of beryllium carbide at the interfaces between the layers which both stabilizes and has a smoothing effect, and appear tomore » be smoother than the interfaces in Mo/Be multilayers.« less

Inventors:
 [1];  [2]
  1. Livermore, CA
  2. (Palo Alto, CA)
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
873720
Patent Number(s):
6229652
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
G - PHYSICS G02 - OPTICS G02B - OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
reflectance; stress; mo2c; multilayers; material; extreme; ultraviolet; euv; reflect; 11; nm; thermal; radiation; stability; consists; alternating; layers; deposited; dc; magnetron; sputtering; substrate; silicon; example; multilayer; 65; 25; measured; degrees; normal; incidence; angle; consisted; 70; bilayers; deposition; period; 78; 83; mtorr; argon; pressure; tensile; 88; mpa; compared; 330; thickness; capped; carbon; produced; increase; reflectivity; similar; capping; raising; 58; formed; initial; testing; shown; formation; beryllium; carbide; interfaces; stabilizes; smoothing; effect; appear; smoother; normal incidence; magnetron sputter; material consists; magnetron sputtering; alternating layers; extreme ultraviolet; incidence angle; radiation stability; dc magnet; dc magnetron; /359/

Citation Formats

Bajt, Sasa, and Barbee, Jr., Troy W. High reflectance and low stress Mo2C/Be multilayers. United States: N. p., 2001. Web.
Bajt, Sasa, & Barbee, Jr., Troy W. High reflectance and low stress Mo2C/Be multilayers. United States.
Bajt, Sasa, and Barbee, Jr., Troy W. Mon . "High reflectance and low stress Mo2C/Be multilayers". United States. https://www.osti.gov/servlets/purl/873720.
@article{osti_873720,
title = {High reflectance and low stress Mo2C/Be multilayers},
author = {Bajt, Sasa and Barbee, Jr., Troy W.},
abstractNote = {A material for extreme ultraviolet (EUV) multilayers that will reflect at about 11.3 nm, have a high reflectance, low stress, and high thermal and radiation stability. The material consists of alternating layers of Mo.sub.2 C and Be deposited by DC magnetron sputtering on a substrate, such as silicon. In one example a Mo.sub.2 C/Be multilayer gave 65.2% reflectance at 11.25 nm measured at 5 degrees off normal incidence angle, and consisted of 70 bilayers with a deposition period of 5.78 nm, and was deposited at 0.83 mTorr argon (Ar) sputtering pressure, with the first and last layers being Be. The stress of the multilayer is tensile and only +88 MPa, compared to +330 MPa of a Mo/Be multilayers of the same thickness. The Mo.sub.2 C/Be multilayer was capped with carbon which produced an increase in reflectivity of about 7% over a similar multilayer with no carbon capping material, thus raising the reflectivity from 58.3% to over 65%. The multilayers were formed using either Mo.sub.2 C or Be as the first and last layers, and initial testing has shown the formation of beryllium carbide at the interfaces between the layers which both stabilizes and has a smoothing effect, and appear to be smoother than the interfaces in Mo/Be multilayers.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {1}
}