Use of diffractive lenses in lithographic projection lenses

H.-J. Rostalski; A. Epple; H. Feldmann

doi:10.1117/12.692314

19 July 2006 Use of diffractive lenses in lithographic projection lenses

H.-J. Rostalski, A. Epple, H. Feldmann

Proceedings Volume 6342, International Optical Design Conference 2006; 63421S (2006) https://doi.org/10.1117/12.692314
Event: International Optical Design Conference 2006, 2006, Vancouver, BC, Canada

Abstract

Projection lenses for high resolution lithography have high NA and work at small wavelengths. In the wavelength regime of VUV (e.g. 193nm), there is a very limited number of optical glasses available, namely fused silica and calcium fluoride. The latter is very expensive and used only sparely, leading to limited possibilities for chromatic correction. In addition to catadioptric approaches, another way to deal with chromatic aberrations is the use of diffractive optical elements (DOEs). They have negative dispersion coupled with positive power and they do not contribute to the Petzval sum. Moreover, it is easy to integrate an aspherical functionality into the structure of the DOE. Usually a DOE is placed close to the aperture stop to correct axial color. The stop of a lithographic projection lens often is located at the largest diameter, causing some serious fabrication difficulties for the DOE. For this reason a class of lenses with intermediate image is of interest. Here, the accessible conjugate of the aperture stop enhances the possibilities to arrange the stop and the DOE. This allows a convenient tradeoff between fabrication challenges and aberration correcting properties. We present different lens designs that take advantage of the named properties of DOEs at high numerical aperture.

Citation Download Citation

H.-J. Rostalski, A. Epple, and H. Feldmann "Use of diffractive lenses in lithographic projection lenses", Proc. SPIE 6342, International Optical Design Conference 2006, 63421S (19 July 2006); https://doi.org/10.1117/12.692314

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