PURPOSE: To reduce scattered light noise from a substrate and detect fine foreign matter, by reducing the incident angle of an illumination optical system, and sufficiently reducing a detection region by using a detection optical system of high detection resolution and a detector having small detection picture elements.
CONSTITUTION: A wafer 401 is mounted on an XYZ stage 561. A measurement point 803 on the wafer 401 is illuminated by a light from semiconductor lasers 531, 532 via condenser objective lenses 535, 536 of an illumination optical system. The scattered light from foreign matter on the measurement point 803 forms an image on a detector 538 via a detection object lens 537 of a detection optical system. In this case, the wafer 401 surface is irradiated from the direction inclined at 60+15 degress to the vertical direction with a laser beam having high output power of (50mW-5W) and short wavelengths of 400-180nm. The reflected scattered light from at least fine particles existing on the wafer 401 is emphasized by diffraction phenomena, and received with a detector 538, and the fine particles are detected by using an electric signal.
KENBO YUKIO
MORIOKA HIROSHI
