Defect detection device, defect detection method, and defect observation device

Abstract

The invention is to provide a defect detection device capable of using a compact optical system to detect a plurality of types of defects with high sensitivity and high speed. The defect detection device includes an irradiation system that irradiates light onto an object to be inspected; an optical system that forms scattered light produced by a light irradiation into an image; a microlens array disposed at an image plane of the optical system; an imaging element that is disposed at a position offset from the imaging plane of the optical system and that images light that passes through the microlens array; a mask image storage unit that stores a plurality of mask images generated for each type of defect or each defect direction; and a calculation unit that carries out mask processing on an image obtained from the imaging element using the plurality of mask images and carries out defect detection processing.