Paper
24 May 2004 Comparison of actinic lens characterization by aerial image evaluation and interferometric testing for 157-nm high-NA micro-objectives
Author Affiliations +
Abstract
Focusing on smaller features for optical inspection or damage repair, smaller wavelengths are used to increase resolution or energy density. Objectives designed for 157nm will use calcium fluoride optics and the objectives need to be evaluated and optimized actinic, at wavelength. Measurement set-up and imaging results are presented through a catadioptric type of micro-objective. The set-ups and measurements are done at the 157nm wavelength as to include all actinic material effects. The imaging set-up uses a custom illuminator to image 130nm features, 500 times enlarged, onto a back-thinned CCD camera in real time. The knowledge of the spatial coherence characteristics of the light source together with the through-focus imaging of structures at various angles allows for the reconstruction of the wave aberrations of the lens. The lens is also measured and optimized using an interferometric set-up and phase shifting techniques.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Horst Schreiber "Comparison of actinic lens characterization by aerial image evaluation and interferometric testing for 157-nm high-NA micro-objectives", Proc. SPIE 5375, Metrology, Inspection, and Process Control for Microlithography XVIII, (24 May 2004); https://doi.org/10.1117/12.533313
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Interferometry

Calcium

Cameras

Wavefronts

Prisms

Interferometers

Dispersion

Back to Top