Device and method for inspecting an object

US7271889B2 · kind B2 · utility

Assignee

• LEICA MICROSYSTEMS CMS GMBH · DE

Inventors

• Franz Cemic · Hachenburg, DE
• Lambert Danner · Wetzlar, DE
• Uwe Graf · Solms, DE
• Robert Mainberger · Bonbaden, DE
• Dirk Sönksen · Schleusingen, DE
• Volker Knorz · Gammertingen, DE

Key dates

• Filing date: Aug 21, 2003
• Grant date: Sep 18, 2007
• Expiry date: Oct 10, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2201/0696
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device and method for inspecting an object (2) uses a bright field illumination beam path (4) of a bright field light source (5), said beam path being formed so that it passes through the projection optics (3), and a dark field illumination beam path (6) of a dark field light source (7), this beam path being formed so that it also passes through the projection optics (3). The object (2) can be projected by the projection optics (3) onto the least one detector (8), and the object (2) is simultaneously illuminated by both light sources (5, 7). In order to simultaneously detect bright field images and dark field images without involving complicated filtering operations, the light used for the dark field illumination is pulsed and the pulse intensity of the light used for the dark field illumination is greater by at least one order of magnitude than the intensity of the continuous light, which is used for the bright field illumination, during a pulsed interval.