Control of defects in EUV multilayers and demonstration of at-wavelength defect characterization by EUV microscopy

Eric Louis; Mark J. H. den Hartog; Edward L. G. Maas; Fred Bijkerk

doi:10.1117/12.309634

5 June 1998 Control of defects in EUV multilayers and demonstration of at-wavelength defect characterization by EUV microscopy

Eric Louis, Mark J. H. den Hartog, Edward L. G. Maas, Fred Bijkerk

Author Affiliations +

Proceedings Volume 3331, Emerging Lithographic Technologies II; (1998) https://doi.org/10.1117/12.309634
Event: 23rd Annual International Symposium on Microlithography, 1998, Santa Clara, CA, United States

Abstract

In EUV optical elements microscopic imperfections in multilayer coatings give rise to increased scatter and reduced integrated reflectivity. If however, the coating is in the object plane of an imaging system, the defects can be imaged. In this study, experimental work is presented on characterization of the defect density and the nature of the defects in molybdenum/silicon-multilayer coatings produced by e-beam evaporation in combination with ion-beam smoothing of the interfaces. To determine in which process steps defects are created, and how these defects can be avoided, several process parameters have been varied during single- and multilayer deposition and ion-polishing. The samples have been characterized by means of an optical particle counter and electron microscopy with energy dispersive x-ray analysis measurement capabilities. To carry out in-depth inspection of the coating, we developed a method to measure the total integrated scatter for EUV radiation from a 1 micrometers spot. Varying the photon energy around the Si- absorption edge enabled us to distinguish between surface defects and in-depth defects that cannot be seen at the multilayer surface.

Citation Download Citation

Eric Louis, Mark J. H. den Hartog, Edward L. G. Maas, and Fred Bijkerk "Control of defects in EUV multilayers and demonstration of at-wavelength defect characterization by EUV microscopy", Proc. SPIE 3331, Emerging Lithographic Technologies II, (5 June 1998); https://doi.org/10.1117/12.309634

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available