TARGET ANALYSIS BY FOCUSING ELLIPSOMETRY

U. Neuschaefer-Rube, W. Holzapfel, F. Wirth

Abstract

Reflection ellipsometry is a proven optical measurement method often used to measure film thicknesses. Classical ellipsometers use an unfocused measurement beam, which causes a low lateral resolution in the order of 1 mm. To determine microstructures ellipsometrically (e.g. in the semiconductor industry), an improved lateral resolution in the order of micrometers is essential. We discuss the problems of focusing ellipsometry, occurring when a reflection ellipsometer is used to measure surface characteristics (topography, material). Different measurement setups are analyzed and compared. Simulating calculations show that particularly the measured values of the phase difference <i>&Delta;</i> are influenced by beam focusing. This leads to errors particularly in the attenuation index <i>k</i> of the surface material.

Keywords

optical measurement, ellipsometry, beam focusing

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IMEKO-WC-2000-TC2-P046.pdf

DOI

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IMEKO TC

TC2 - Photonics

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