| 摘要 |
PURPOSE:To reduce the undetected error rate of a foreign matter by constituting the title device so that is can detect the intensity of two polarization components of each different polarization angle of the reflected scattering light from the surface of an inspection object substrate. CONSTITUTION:The title device is constituted so that an inspection object substrate O in which a circuit pattern C is drawn on the surface is brought to linear moving scan in the (x) direction on the horizontal plane, and also, a laser beam L having a prescribed polarization angle is radiated, while bringing it to reciprocating linear scan within a prescribed range in the (y) direction being orthogonal to the (x) direction, and the reflected scattering light R is measured by a detecting optical system A. In such a state, one luminous flux RO in the scattered light R is separated into two luminous fluxes r1, r2 by a beam splitter S, and made incident on first and the second photodetectors D1, D2 through first and the second analyzers H1, H2. Subsequently, a ratio (or a difference) of the intensity of both polarization components which is detected by the detectors D1, D2 is measured by a comparing means Q, and the decision of existence of a foreign matter on the surface of the substrate O, and a discrimination between a 45 deg. circuit pattern, etc. and the foreign matter can be executed surely. |
