Abstract: Provided are a defect inspection apparatus having a large range for receiving light scattering from fine defects while securing a sufficiently large signal strength; and a defect inspection method for the same. The defect inspection apparatus includes: a stage part capable of traveling relative to optical systems with a substrate to be inspected mounted on the stage part; an illumination optical system for illuminating an inspection area on the substrate; a detection optical system for detecting light coming from the inspection area on the substrate; an image sensor for converting, to a signal, an image which is formed on the image sensor by the detection optical system; a signal processor for detecting defects by processing the signal from the image sensor; and a plane reflecting mirror, arranged between the detection optical system and the substrate, for transmitting the light, which comes from the substrate, to the detection optical system.

Abstract: A defect inspection apparatus includes: stages each mounting an inspecting object on which a circuit pattern having a group of parallel lines is formed, and each running perpendicular or parallel to the group of lines; an illumination optical system which illuminating a surface of the inspecting object with a slit beam being slit light so that a longitudinal direction of the slit beam is substantially perpendicular to the running directions of the stages, and which has a first inclined angle formed by the direction of the group of lines and a projection line, of an optical axis of the slit beam, to the inspecting object; a spatial filter that shields or transmits reflected and scattered light of the inspecting object according to a difference in distribution of orientation; and a detection optical system that detects the reflected and scattered light transmitted through the spatial filter by image sensors.

Abstract: A wafer surface observing apparatus for inspecting a peripheral portion of an object has (A) a lens system and a CCD camera for taking images of the peripheral portion of the object, (B) storage for storing image data about the taken images, and (C) display for displaying the image data stored in the storage device. In particular, the present apparatus can have functions of rotating the object placed on a prealignment portion, recording images of one full outer periphery of an end portion of the object by the lens system and CCD camera into the location where the orientation flat portions or notched portions of the object are placed in position, accepting the images into the storage device, and displaying the images on a CRT.

Abstract: A defect inspecting apparatus of the invention solves a problem that in a defect inspecting apparatus, because of improving detection sensitivity of a microscopic defect by reducing a detection pixel size, a focal depth becomes shallow, a height of imaging is varied due to environmental change and the detection sensitivity of a defect becomes unstable. This apparatus comprises an XY stage, which carries a substrate to be inspected and scans in a predetermined direction, and a mechanism having a system of irradiating a defect on the inspected substrate at a slant and detecting the defect by a detection optical system disposed on the upper side, which corrects a height of imaging in real time for change in temperature and barometric pressure in order to keep the imaging in a best condition.

Abstract: A laser length measuring instrument in which a first and a second sinusoidal wave interference signals differing in phase by .pi./2 are generated from a plurality of interference wave signals received from an interferometer; a plurality of third sinusoidal wave interference signals differing in phase by m.pi./2 n (where n=integer 2 or greater; m=positive integer sequentially selected from among 0<m.pi./2n<.pi.