INSPECTION SYSTEM

摘要

To improve sensitivity of a defect inspection, it is required to decrease influence of excessive diffraction from a spatial filter. Further, it is preferable to secure signal intensity from defects and particles as much as possible, while the influence of the excessive diffraction is decreased as much as possible. The present invention is characterized in setting a width of a spatial filter surface such that an unnecessary image caused by diffraction, that is, an intensity of the excessive diffraction is sufficiently small with respect to an intensity of a desired image. In the present invention, an SN ratio that is an index for deciding a width of the spatial filter is calculated from a region subjected to the influence of the excessive diffraction in an inspection image, and a width of a shield unit of the spatial filter is set so as to maximize the SN ratio.

主权项

1. An inspection system comprising:
an illumination optical system that illuminates light on a substrate; a first detection optical system that forms a first image by collecting and imaging light from the substrate; a first spatial filter that is disposed on an optical path of the first detection optical system; and a processing unit, wherein the processing unit obtains a first diffraction light component, which is generated from the first spatial filter, from the first image, and the processing unit obtains a first index for deciding a width of the first spatial filter from the first diffraction light component.