Patent ID: 6809809
Filing Date: 2004-10-26
Classification: G01N

Abstract:
An optical inspection module for inspecting a substrate having first and second opposite planar surfaces, the module comprising:a substrate holding position; a first measurement instrument comprising: a first illumination path extending to the substrate holding position and having a grazing angle of incidence with respect to the first surface of the substrate when the substrate is held in the substrate holding position, wherein the first illumination path illuminates substantially the entire first surface; a first optical element, which is oriented to collect non-specularly reflected light that is scattered from the first illumination path by the first surface, the first optical element having a focal plane; and a first photodetector having a plurality of pixels which are positioned within the focal plane of the first optical element, wherein each pixel corresponds to an area on the first surface and the plurality of pixels together form a field of view that covers substantially the entire first surface; and a second measurement instrument comprising a sensor oriented for sensing a physical characteristic of the second surface when the substrate is held in the substrate holding position and the first surface is being illuminated.