Patent ID: 7190447
Filing Date: 2007-03-13
Classification: G01B,G01N,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 not equal to zero; separating a scattered light intensity into a first scattered light beam and a second scattered light beam, wherein the scattered light intensity comprises light intensity scattered from the first position and the second position; detecting the first scattered light beam; and detecting the second scattered light beam; wherein the first surface scattered light intensity is collected with a first elliptical mirror and wherein the second surface scattered light intensity is collected with a second elliptical mirror.