Substrate inspection apparatus and mask inspection apparatus

摘要

The invention is directed to the provision of a substrate inspection apparatus and a mask inspection apparatus that can sufficiently correspond to the refinement of the patterns formed on the substrate and the influence caused by the diffracted light and scattered light is reduced. In the substrate inspection apparatus according to the invention, the acquisition of the inspection data for a defect and the acquisition of the focus data of the objective lens are performed in parallel. An autofocus apparatus for controlling the position of the objective lens along its optical axis comprises focus error detection means (40) and focus control signal generation means (60) for generating a focus control signal for controlling the position of the objective lens for each scan line using a focus data signal composed of an objective position signal or the objective position signal to which a focus error signal is added. When "i" is assumed as a positive integer and "m" is as a natural number, the focus data signal which was acquired during the scanning period of i-th scan line is used to produce the focus control signal used to scan the (i+2m)-th scan line.