Abstract: A method of providing high accuracy inspection or metrology in a bright-field differential interference contrast (BF-DIC) system is described. This method can include creating first and second beams from a first light beam. The first and second beams have round cross-sections, and form first partially overlapping scanning spots radially displaced on a substrate. Third and fourth beams are created from the first light beam or a second light beam. The third and fourth beams have elliptical cross-sections, and form second partially overlapping scanning spots tangentially displaced on the substrate. At least one portion of the substrate can be scanned using the first and second partially overlapping scanning spots as the substrate is rotated. Radial and tangential slopes can be determined using measurements obtained from the scanning using the first and second partially overlapping scanning spots. These slopes can be used to determine wafer shape or any localized topography feature.

Abstract: A method of providing high accuracy inspection or metrology in a bright-field differential interference contrast (BF-DIC) system is described. This method can include creating first and second beams from a first light beam. The first and second beams have round cross-sections, and form first partially overlapping scanning spots radially displaced on a substrate. Third and fourth beams are created from the first light beam or a second light beam. The third and fourth beams have elliptical cross-sections, and form second partially overlapping scanning spots tangentially displaced on the substrate. At least one portion of the substrate can be scanned using the first and second partially overlapping scanning spots as the substrate is rotated. Radial and tangential slopes can be determined using measurements obtained from the scanning using the first and second partially overlapping scanning spots. These slopes can be used to determine wafer shape or any localized topography feature.

Abstract: Systems and methods for inspecting an edge of a specimen are provided. One system includes an illumination subsystem configured to direct light to the edge of the specimen at an oblique angle of incidence. The plane of incidence of the light is substantially perpendicular to a plane substantially tangent to the edge of the specimen. The system also includes a detection subsystem configured to collect light scattered from the edge and to generate signals responsive to the scattered light. One method includes directing light to the edge of the specimen at an oblique angle of incidence. The plane of incidence is substantially perpendicular to a plane substantially tangent to the edge of the specimen. The method also includes collecting light scattered from the edge and generating signals responsive to the scattered light. The signals described above can be used to detect defects on the edge of the specimen.