Apparatus for examining the surface of a substrate
AssigneeNikon Corporation
InventorKazunori Imamura
Life of this patent
Estimating the term…
Abstract
An apparatus for examining the surface of a substrate comprises irradiating means for supplying a light beam which scans the surface of the substrate, first and second light-receiving means for individually receiving scattered lights travelling in different first and second directions from the surface of the substrate and individually producing first and second output signals conforming to the intensities of the received lights, and means for discriminating the directional characteristics of the scattered lights on the basis of the time phase shift between the first and second output signals.
Claims8
An apparatus for examining the surface of a substrate, comprising:
- irradiating means for supplying a light beam which scans the surface of said substrate;
- first and second light-receiving means for individually receiving scattered lights travelling in different first and second directions from the surface of said substrate and individually producing first and second output signals conforming to the intensities of the received lights;
- and
- means for discriminating the directional characteristics of said scattered lights on the basis of the time phase shift between said first and second output signals.
An apparatus for detecting a foreign particle present on the surface of substrate, comprising:
- means for supplying a light beam which scans the surface of said substrate;
- first and second light-receiving means for individually receiving scattered lights travelling in different first and second directions from the surface of said substrate and individually producing first and second outupt signals conforming to the intensities of the received lights;
- means for discriminating the directional characteristics of said scattered lights on the basis of the time phase shift between said first and second output signals;
- and
- means for determining the presence of said foreign particle on the basis of said first and second output signals and the directional characteristics of said scattered lights.
An apparatus for examining the surface of a substrate, comprising:
- irradiating means for supplying a light beam which scans the surface of said substrate along scanning lines;
- first and second light-receiving means for individually receiving scattered lights travelling in different first and second directions from the surface of said substrate and individually producing first and second output signals conforming to the intensities of the received lights;
- and
- means for discriminating the directional characteristics of said scattered lights on the basis of the difference between the variation of said first output signal occuring during successive scans of said light beam along said scanning lines and the variation of said second output signal occurring during successive scans of said light beam along said scanning lines.
Dependencies are inferred from the claim text.