DEVICE AND METHOD FOR MEASURING WAFERS

Abstract

A device (14) for measuring wafers (10) comprises an optical coherence tomograph (22) that generates a measurement light beam (24) and directs it onto the wafer (10) via an optical system (38), and a scanning device (26) that deflects the measurement light beam (24) in two spatial directions. A control unit (36) controls the scanning device (26) so that the measurement light beam (24) successively scans the surface of the wafer (10) at several measurement points. Two measurement points are separated by a distance d <sub>max</sub> of 140 mm ≤ d <sub>max</sub> ≤ 600 mm. An evaluation unit (57) calculates distance values and/or thickness values from interference signals provided by the optical coherence tomograph (22). Additional measures, such as a calibration measurement, are provided to reduce measurement errors resulting from field curvature caused by the scanning device.

Inventors

Weiß, Dr. Stephan
MIETH, Dr. Simon
Weigelt, Corinna
Beck, Dr. Tobias

Assignees

Precitec Optronik GmbH

Dates

Publication Date: 20260513
Application Date: 20230125