Inspecting method using an electro optical detector

Abstract

An inspecting method using an electro-optical detecting device is disclosed. The electro-optical detecting device includes: an upper substrate and a lower substrate; a nematic liquid crystal layer interposed between the upper substrate and the lower substrate; a transparent electrode interposed between the nematic liquid crystal layer and the upper substrate, the transparent electrode connected to a device under test (DUT) via a power supply; a polarizing plate located over the nematic liquid crystal layer; and a reflecting plate located under the nematic liquid crystal layer. A method using the electro-optical detecting device includes applying a voltage between the transparent electrode and the DUT to generate an electric field across the liquid crystal layer; illuminating the detector and capturing an image of the detector using the light reflected from the detector; and determining the DUT has some defects from the image of the detector by an abnormal electric field generated between the transparent electrode and the DUT.