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Title: Method and apparatus for detecting the presence and thickness of carbon and oxide layers on EUV reflective surfaces

Abstract

The characteristics of radiation that is reflected from carbon deposits and oxidation formations on highly reflective surfaces such as Mo/Si mirrors can be quantified and employed to detect and measure the presence of such impurities on optics. Specifically, it has been shown that carbon deposits on a Mo/Si multilayer mirror decreases the intensity of reflected HeNe laser (632.8 nm) light. In contrast, oxide layers formed on the mirror should cause an increase in HeNe power reflection. Both static measurements and real-time monitoring of carbon and oxide surface impurities on optical elements in lithography tools should be achievable.

Inventors:
Issue Date:
Research Org.:
Sandia National Lab. (SNL-CA), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1175219
Patent Number(s):
6847463
Application Number:
10/163,477
Assignee:
EUV, LLC (Santa Clara, CA)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01B - MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING

Citation Formats

Malinowski, Michael E. Method and apparatus for detecting the presence and thickness of carbon and oxide layers on EUV reflective surfaces. United States: N. p., 2005. Web.
Malinowski, Michael E. Method and apparatus for detecting the presence and thickness of carbon and oxide layers on EUV reflective surfaces. United States.
Malinowski, Michael E. Tue . "Method and apparatus for detecting the presence and thickness of carbon and oxide layers on EUV reflective surfaces". United States. https://www.osti.gov/servlets/purl/1175219.
@article{osti_1175219,
title = {Method and apparatus for detecting the presence and thickness of carbon and oxide layers on EUV reflective surfaces},
author = {Malinowski, Michael E.},
abstractNote = {The characteristics of radiation that is reflected from carbon deposits and oxidation formations on highly reflective surfaces such as Mo/Si mirrors can be quantified and employed to detect and measure the presence of such impurities on optics. Specifically, it has been shown that carbon deposits on a Mo/Si multilayer mirror decreases the intensity of reflected HeNe laser (632.8 nm) light. In contrast, oxide layers formed on the mirror should cause an increase in HeNe power reflection. Both static measurements and real-time monitoring of carbon and oxide surface impurities on optical elements in lithography tools should be achievable.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2005},
month = {1}
}