Apparatus And Method For Inspecting Defects

Abstract

A defect inspection apparatus includes an irradiation optical system 20 , a detection optical system 30 , and an image processor 40 . In the irradiation optical system, a mirror 2603 is disposed to reflect downward a beam flux that has been guided to a first or second optical path, and a cylindrical lens 251 and an inclined mirror 2604 are disposed to focus the beam flux that has been directed downward by the mirror, at an inclination angle from a required oblique direction extending horizontally, onto a substrate 1 to be inspected, as a slit-shaped beam 90.

1 . A defect inspection apparatus, comprising:
 a stage which moves to travel after a substrate to be inspected is mounted on the stage, the substrate having a circuit pattern formed thereon;   an irradiation optical system that guides a beam flux emitted from a laser light source from a principal optical path to a first or second optical path, focuses the beam flux that has been guided to the first or second optical path into a slit-shaped beam at an angle of inclination to the surface of the substrate to be inspected, the slit-shaped beam being formed up by fluxes of light that are substantially parallel in a longitudinal direction of the slit-shaped beam, and irradiates the substrate with the slit-shaped beam such that the longitudinal direction is at a substantially right angle to a moving direction of the stage;   a detection optical system that uses an objective lens to converge reflected/scattered light obtained from contamination or defects present on the substrate that has been irradiated with the slit-shaped beam, and uses an image sensor to receive the reflected/scattered light that has been converged, so as to convert the received light into a signal, and to detect the signal; and   an image processor that extracts, on the basis of the signal that has been detected by the image sensor of the detection optical system, a signal indicative of the defect;   wherein the irradiation optical system includes:   a downward reflecting mirror that reflects downward the beam flux that has been guided to the first or second optical path; and   a cylindrical lens and an inclined mirror each for focusing the beam flux that has been directed downward by the downward reflecting mirror onto the substrate to be inspected, as the slit-shaped beam, from the direction having the inclination angle.