Patent ID: 6654113
Filing Date: 2003-11-25
Classification: G01N

Abstract:
A surface inspection apparatus comprising;an illuminating device that illuminates a test piece having a plurality of repetitive patterns with different pitches formed at a surface thereof; an image-capturing device that captures an object image based upon diffracted light originating from the test piece; a tilt angle changing device that changes a tilt angle of the test piece by controlling a holder that holds the test piece; a condition control device that executes a tilt angle changing operation in which the tilt angle changing device changes the tilt angle of the test piece plural times; a condition determining device that takes in object images, each captured by said image-capturing device every time the tilt angle is changed in the tilt angle changing operation and determines an optimal tilt angle based on the object images captured for each tilt angle change; and a memory that stores the optimal tilt angle determined by the condition determining device; wherein: the surface of the test piece is inspected with the optimal tilt angle stored in the memory.