APPARATUS AND METHOD FOR INSPECTING SEMICONDUCTOR WAFER

摘要

A semiconductor wafer surface inspecting apparatus detects a low-height flat LAD (large area detect) by discriminating it from particles. The inspecting apparatus detects a point (400) where an upward inclination of a surface of a wafer (200) exists, and a point (402) where a downward inclination of that exists, by scanning the surface of the semiconductor wafer (200), vertically applying two parallel laser beams on each point on the surface and by measuring the phase difference between two reflecting beams. An area (404) wherein a pair of or a group of the upward inclination point (400) and the downward inclination point (402) exist within a range of a prescribed mutual distance is estimated as the LAD.