Patent ID: 9157870
Filing Date: 2015-10-13
Classification: G01N

Abstract:
1. A pattern test apparatus which tests pattern defects by using a pattern image obtained by applying light to a test sample, comprising: a light source configured to apply test light of a predetermined wavelength to the test sample; a polarizing beam splitter which reflects the light from the light source, and guides the light onto the test sample; an imaging device which receives light which has been reflected by the test sample and reflected by the polarizing beam splitter; an optical system which forms a Fourier transform plane of the test sample between the test sample and the polarizing beam splitter; and a polarizing controller disposed in the Fourier transform plane, the polarizing controller including a first region which lets the test light through, and a second region which has an area greater than that of the first region and lets the light reflected by the test sample through, the first region and the second region having different retardation quantities.