摘要 |
PROBLEM TO BE SOLVED: To quickly and precisely inspect a defect such as a very small contaminant by calculating dispersion based on signals in a portion with the same circuit patterns formed or in its vicinity, and by extracting a signal indicating the defect such as the very small contaminant out of detected signals based on a threshold set on the basis of a result calculated hereinbefore. SOLUTION: An illumination optical system 100 having a laser beam 101, lenses 102-104, a beam splitter and the like has a precdribed inclination with respect to a main straight line group of a circuit pattern, and an inspected objective substrate 1 is irradiated subtantially orthogonally to a traveling direction of a substrate mounting table 304 for mounting the objective substrate 1. An inspecting optical system 200 detects reflected scattered light provided by a defect such as a contaminant existing on the substrate 1, using image sensors 205, 206 through lenses 201, 203 and a beam aplitter 204, to feed signals to a processing circuit 400. A threshold as a determination reference is set in a defect determining process in the circuit 400 based on a dispersion of the resulting signals, and the signal indicating the defect such as the contaminant is extracted, based on the set threshold.
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