Translator Disclaimer
2 August 2004 Inverse propagation algorithm for angstrom accuracy interferometer
Author Affiliations +
This paper will illustrate several approaches to retrieving the shape of aspherical reflective surfaces as used in EUV Lithography, from measurements from a previously reported angstrom-accuracy interferometer. First, the working principles of the interferometer will be reviewed, and typical measurement data expected from the instrument will be presented. Several methods will then be introduced for retrieving the reflector shape from such measurements. These methods will include approaches based on ray tracing, approximate diffraction calculations, and linearization of rigorous diffraction calculations which use a novel numerical scheme to reduce calculation time of the diffraction integral. The methods will be compared on the basis of accuracy, calculation time and extendibility.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Max Lukas Krieg and Joseph J. M. Braat "Inverse propagation algorithm for angstrom accuracy interferometer", Proc. SPIE 5531, Interferometry XII: Techniques and Analysis, (2 August 2004);

Back to Top