Leica Microsystems Wetzlar Gmbh

Leica Microsystems Jena Gmbh

Guenter Hoffmann

Joachim Wienecke

Uwe Graf

Michael Graef

Karl-Heinz Franke

Lutz Jakob

Klaus Hallmeyer

A method for focusing on disk-shaped objects with patterned and unpatterned surfaces includes imaging of the patterned and unpatterned surfaces on a disk-shaped object for defect detection and defect classification by using various preset values of a focus regulation system to acquire the image sequence. At least one preset value is learned on the basis of an image sequence at least at one position in a substantially flat reference region of the surface of the disk-shaped object. A regulated adjustment is provided of a measurable distance from a carrier plane to a reference plane, wherein the carrier plane serves as a support for the disk-shaped objects. The distance is adjusted by applying the at least one preset value, which is overlaid on the regulation system, a focus state is evaluated by an image processor according to at least one rule, and the at least one preset value is ascertained therefrom.

Method for focusing of disk-shaped objects with patterned surfaces during imaging

An optical measurement arrangement includes an ellipsometer ( ) and a device for ascertaining and correcting directional deviations between the line normal to the specimen surface and the angle bisector ( ) between the incident and return beams ( ) of the ellipsometer ( ). A measurement arrangement includes a mirror objective and a device for ascertaining directional deviations between the line normal to the specimen surface and the optical axis of the mirror objective, which has a deflection element in the unused aperture space of the mirror objective. A direction monitoring beam ( ) is directed onto the specimen (P). An optical element for imaging the return reflection of the direction monitoring beam ( ) onto an area detector that is connected to an evaluation circuit ( ) is also provided. Positioning commands for a specimen stage ( ) are available at the outputs of the evaluation circuit ( ). By way of the control commands, the specimen stage is caused to tilt until the return reflection on the area detector has assumed the position at which the direction of the normal line corresponds to the direction of the angle bisector ( ).

Optical measurement arrangement and method for inclination measurement

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Jena, Germany

Guenter Hoffmann