Patent attributes
An apparatus, system and method for measuring a feature of a three-dimensional object, such as a wafer carrier, are provided. The apparatus is for use with an optical scanner and comprises a mounting structure adapted to be disposed on the scanner. The mounting structure has a calibration mark adapted to be read by the scanner and is adapted to position the object so that it is at a first pre-determined distance from the calibration mark. In one aspect of the present invention, the mounting structure further comprises an alignment surface adapted to abut the object. The alignment surface is disposed at a second pre-determined distance from the calibration mark. In another aspect of the present invention, the alignment surface is adapted to abut the object at a point spaced apart from the scanning surface.
