Patent ID: 6909500
Filing Date: 2005-06-21
Classification: G01B,H01L

Abstract:
1. A method for measuring a defect on a surface of an object, comprising: directing a first light beam in a first plane of incidence toward a first position on the object; directing a second light beam in a second plane of incidence toward a second position on the object, wherein the angle between the first plane of incidence and the second plane of incidence is at an angle that is not one of substantially zero degrees, subtantially 45 degrees and subtantially 135 degrees; detecting a first scattered light intensity, wherein the first scattered light intensity comprises light intensity scattered from the first position; detecting a second scattered light intensity, wherein the second scattered light intensity comprises light intensity scattered from the second position; comparing the first scattered light intensity and the second scattered light intensity to determine a first aspect ratio of a defect on the surface of the object.