Defect inspection apparatus and method
AssigneeHitachi High-Technologies Corporation
InventorsYukihiro Shibata, Yasuhiro Yoshitake
Life of this patent
Estimating the term…
Abstract
In a defect inspection apparatus for inspecting a wafer provided with a circuit pattern for defects, the illuminating direction of illuminating light rays is selectively determined such that an area containing a defect that scatters light of high intensity coincides with the aperture of a dark-field detecting system, and such that regularly reflected light regularly reflected by a pattern, which is noise to defect detection, does not coincide with the aperture of the dark field detecting system.
Claims16
A defect inspection method of inspecting a specimen provided with a pattern for defects, said defect inspection method comprising:
- projecting first illuminating light rays on the specimen from a direction of a first main pattern included in the pattern, and detecting first scattered light scattered by an illuminated first area, to form a digital image of the first scattered light;
- projecting second illuminating light rays on the specimen from a direction of a second main pattern included in the pattern, and detecting second scattered light scattered by an illuminated second area, to form a digital image of the second scattered light;
- and
- determining presumable defects by comparing the first and the second digital image.
A defect inspection method of inspecting a specimen provided with a pattern for defects, said defect inspection method comprising:
- scanning the specimen in a horizontal plane;
- illuminating a linear area on the specimen from a direction perpendicular to a direction in which the specimen is scanned in a parallel illumination mode, by a first illuminating system;
- illuminating a linear area on the specimen from a direction parallel to the direction in which the specimen is scanned in a condensed illumination mode, by a second illuminating system;
- capturing first and second scattered light rays by a detecting optical unit having a NA (numerical aperture) of 0.7 or above;
- separating the scattered first illuminating light flux and the scattered second illuminating light flux captured by the detecting optical unit, so as to direct separated light to travel along two optical paths, respectively;
- detecting images formed on the optical paths by image sensors disposed on the optical paths, respectively;
- and
- determining presumable defects by comparing the images detected by the image sensors.
A defect inspection apparatus for inspecting a specimen provided with a pattern for defects, said defect inspection apparatus comprising:
- a stage configured to support a specimen thereon;
- a first illuminating optical system configured to project first illuminating light rays on the specimen from a direction of a first main pattern included in the pattern;
- a second illuminating optical system configured to project second illuminating light rays on the specimen from a direction of a second main pattern included in the circuit pattern;
- a first optical detection system disposed above the specimen, to detect first scattered light flux scattered by a first area illuminated with the first illuminating light rays;
- a second optical detection system disposed above the specimen, to detect second scattered light flux scattered by a second area illuminated with the second illuminating light rays;
- and
- an image processing unit configured to determine presumable defects by comparing a first digital image formed by the first optical detection system and a second digital image formed by the second optical detection system.
Dependencies are inferred from the claim text.