Sentech Instruments Gmbh

Helmut Witek

Uwe Richter

Albrecht Kruger

Uwe Wielsch

Georg Dittmar

Michael Arena

This invention concerns an ellipsometer for the examination of a sample whereby the ellipsometer has a broadband light source on the emitter side and a detector on the receiver side for a receiver light beam reflected from the sample. A refractive optic for the generation of a measuring spot on the sample and an aperture arranged on the emitter side for the definition of a measuring spot on the sample. The spectroscopic ellipsometer of the present invention makes it possible to easily produce a precisely defined measuring spot on the sample.

Ellipsometer

Characteristic values of transparent layers in the nanometer range, such a layer thickness and refractive index, can be determined with a spectro-ellipsometer. The task is to determine these values even with a less elaborate ellipsometer which only operates at one or a few wavelengths. In accordance with the invention, first at least one pair of the ellipsometric angles psi and delta are measured with at least one angle of incidence of the light beams on the sample for at least one ellipsometer wavelength, from which at least one characteristic value is determined for one ellipsometer period. Furthermore, the wavelength-dependent reflection of the probe in the wavelength range of interest is photometrically measured and from this the spectral dependency of the characteristic value is determined with the ellipsometrically measured characteristic value.

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Krailing, Germany

Helmut Witek