The Effects of Oxygen Plasma on the Chemical Composition and Morphology of the Ru Capping Layer of the Extreme Ultraviolet (EUV) Mask Blanks
The Effects of Oxygen Plasma on the Chemical Composition and Morphology of the Ru Capping Layer of the Extreme Ultraviolet (EUV) Mask Blanks
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氧等离子体对极紫外 (EUV) 掩模基板 Ru 覆盖层化学成分和形貌的影响
DOI:
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发表时间:
2008
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影响因子:
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通讯作者:
Leonid Belau
中科院分区:
文献类型:
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作者:
Leonid Belau
P-5B-03 The effects of oxygen plasma on the chemical composition and morphology of the Ru capping layer of the extreme ultraviolet (EUV) mask blanks Leonid Belau 1 , Jeong Y. Park 2 , Ted Liang 4 , and Gabor A. Somorjai 1,2,3* Department of Chemistry, University of California, Berkeley, California 94720 Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 Components Research, Technology and Manufacturing Group, Intel Corporation, Santa Clara, CA 95054 ABSTRACT Contamination removal from extreme ultraviolet (EUV) mask surfaces is one of the most important aspects to improve reliability for the next generation of EUV lithography. We report chemical and morphological changes of the ruthenium (Ru) mask surface after oxygen plasma treatment using surface sensitive analytical methods: X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and transmission electron microscopy (TEM). Chemical analysis of the EUV masks shows an increase in the subsurface oxygen concentration, Ru oxidation and surface roughness. XPS spectra at various photoelectron takeoff angles suggest that the EUV mask surface was covered with chemisorbed oxygen after oxygen plasma treatment. It is proposed that the Kirkendall effect is the most plausible mechanism that explains the Ru surface oxidation. The etching rate of the Ru capping layer by oxygen plasma was estimated to be 1.5±0.2 A/min, based on TEM cross sectional analysis. * Corresponding author, e-mail address: somorjai@berkeley.edu