US Patent 7151609 Determining wafer orientation in spectral imaging

Devices and methods for determining wafer orientation in spectral imaging are described. The devices and methods generate an image of a wafer that includes at least one spectral dimension. One or more properties are determined from the spectral dimension, and a map is generated based on the property. The generated map is compared to at least one other map, and data or information of the comparison is used to locate a region of the wafer, for example a measurement pad or other structure.