Pattern inspecting apparatus, pattern inspecting method, aligner, and method of manufacturing electronic device

摘要

Disclosed is an overlapping precision measuring apparatus for constituting the inventive pattern inspection apparatus, which is capable of accurately inspecting overlapped condition of aluminum wiring pattern and resist pattern formed on a semiconductor wafer even in presence of a stepped gap. The inventive pattern inspecting apparatus comprises the following: an optical frequency shifter for splitting a laser beam emitted from a laser-beam emitting source into a plurality of frequencies; an optical means such as an object lens for condensing laser beams comprising plural frequencies split via the optical frequency shifter towards a specific pattern subject to inspection; an optical detector for receiving reflected laser beams comprising plural frequencies irradiated onto a pattern subject to inspection via an optical means; and an analyzer for analyzing actual position of the pattern subject to inspection based on the reflected laser beams received by the optical detector.