Vistec Semiconductor Systems Gmbh

Leica Microsystems Jena Gmbh

Vistec Semiconductor Systems Jena Gmbh

Gert Weniger

Joachim Wienecke

Ulrich Pohlmann

Detlef Michelsson

Henning Backhauss

Thomas Iffland

Frank Rennicke

The invention relates to an apparatus for the determination of the position of a disc-shaped object, particularly of a wafer (). Thereby, a mount () for supporting the sensor device () is provided on a movable carrier ().

Apparatus and method for the determination of the position of a disk-shaped object

A method of detecting incomplete edge bead removal from a disk-like object is disclosed. First a peripheral area of a disk-like reference object is imaged. Marks are then defined in the peripheral area of the reference object. Finally, images of peripheral areas of a plurality of disk-like objects of the same batch are recorded. The inspection of the disk-like objects is limited to the locations of the marks defined on the reference object.

Method of detecting incomplete edge bead removal from a disk-like object

A sample P is illuminated by a measurement light beam with an incidence angle differing from 0&#xb0;; light reflected therefrom is detected; intensity values are recorded and evaluated; and the opening of a field stop is imaged onto a receiving surface, thereby generating an image. In such a method, a value of 'light' or 'dark' is allocated to each intensity value as a function of a brightness threshold; the smallest rectangle that encloses all &#x201c;light&#x201d; positions on the receiving surface is determined; the geometric center point of that rectangle is determined; the position of that point is compared with the position on the receiving surface that corresponds to the geometric center point of the image generated by the field stop in the focused state; and a change in the distance between the sample and the imaging optical system corresponding to the distance between the two points is effected.

Method for automatic focusing an imaging optical system on the surface of a sample

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Jena, Germany

Gert Weniger