Foreign substance inspecting apparatus and method thereof
AssigneeNikon Corporation
InventorsKinya Kato, Yumi Nakagawa
Life of this patent
Estimating the term…
Abstract
A foreign substance inspecting apparatus and method for detecting a foreign substance on a surface, includes a light source for providing light; a plurality of condensing optical systems for collecting the light from the light source and for forming a plurality of light spots on the surface; a scanning system for scanning the surface using the light spots formed by the condensing optical systems; a detecting optical system for detecting light scattered from at least one of the light spots by the foreign substance on the surface; and a surface shape measuring system for measuring a shape of the surface, wherein a focus of each one of the condensing optical systems is individually adjusted according to the surface shape measured by the surface shape measuring system.
Claims17
A foreign substance inspecting apparatus for detecting a foreign substance on a surface, comprising:
- a light source for providing light;
- a plurality of condensing optical systems for collecting the light from the light source and for forming a plurality of light spots on the surface;
- a scanning system for scanning the surface using the light spots formed by the condensing optical systems;
- a detecting optical system for detecting light scattered from at least one of the light spots by the foreign substance on the surface;
- and
- a surface shape measuring system for measuring a shape of the surface, wherein a focus of each one of the condensing optical systems is individually adjusted according to the surface shape measured by the surface shape measuring system.
A method for detecting the presence of a foreign substance on a surface, comprising the steps of:
- providing light from a light source;
- collecting the light from the light source using a plurality of condensing optical systems;
- forming a plurality of light spots on the surface from the light collected by the plurality of condensing optical systems;
- scanning the surface using the light spots formed by the condensing optical systems;
- detecting light scattered by the foreign substance on the surface from at least one of the light spots;
- measuring a shape of the surface;
- and
- individually adjusting a focus of each one of the condensing optical systems according to the measured surface shape.
Dependencies are inferred from the claim text.