Abstract: A device for measuring wafers includes an optical coherence tomograph and a scanning device that scans the surface of the wafer successively at a plurality of measuring points. Two measuring points have a distance dmax of 140 mm?dmax?600 mm. An evaluation unit calculates distance values and/or thickness values from the interference signals provided by the optical coherence tomograph.

Abstract: A device for measuring wafers includes an optical coherence tomograph, which generates a measuring light beam and directs it onto the wafer via an optical system. A scanning device deflects the measuring light beam in two spatial directions. A control unit controls the scanning device so that the measuring light beam scans the surface of the wafer successively at several measuring points. Two measuring points have a distance dmax of 140 mm?dmax?600 mm. An evaluation unit calculates distance values and/or thickness values from the interference signals provided by the optical coherence tomograph and, based on the distance values and/or thickness values, at least one characteristic quantity of the wafer such as TTV, warp or bow.

Abstract: A device for measuring wafers includes an optical coherence tomograph and a scanning device that scans the surface of the wafer successively at a plurality of measuring points. Two measuring points have a distance dmax of 140 mm?dmax?600 mm. An evaluation unit calculates distance values and/or thickness values from the interference signals provided by the optical coherence tomograph.

Abstract: The invention relates to a device for optical measurement of a thickness of an intransparent layer on a substrate, comprising first means for optical distance measurement configured to measure a first distance between a first reference plane and a first surface of the intransparent layer, and second means for optical distance measurement configured to measure a second distance between a second reference plane and a second surface of the intransparent layer. The second means measures a third distance between the second reference plane and a surface of the substrate. The thickness of the intransparent layer is computed from the first distance and the second distance. The measurement of the third distance is used to take into account the influence of the optical effect of the substrate on the distance measurement of the second distance. The invention also relates to a method for optical measurement of a thickness of an intransparent layer on a substrate.