Arrangement and method for detecting defects on a substrate in a processing tool

• Main Authors: OTTO, RALF, SCHEDEL, THORSTEN, SEIDEL, TORSTEN, MARX, ECKHARD, SCHUMACHER, KARL
• Format: Patent
• Language: English
• Published: 11.09.2003
• Edition: 7
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; BASIC ELECTRIC ELEMENTS; CINEMATOGRAPHY; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROGRAPHY; HOLOGRAPHY; MATERIALS THEREFOR; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; SEMICONDUCTOR DEVICES

A processing tool (1) for manufacturing semiconductor wafers (2a), e.g. a lithography cluster, comprises a device transfer area (8) with an optical sensor (10), preferably a CCD camera, and an illumination system (11) mounted within, such that a substrate (2) being transferred to or from one of its processing chambers of a coater, an exposure tool and a developer (1a, 1b, 1c) can be scanned during its movement at low resolution. The substrate (2) may be either a semiconductor wafer to be manufactured or a reticle or mask used to perform an exposure on said wafer. The scanning is performed twice, prior and after processing in at least one the processing chambers of a coater, an exposure tool and a developer (1a, 1b, 1c) of the processing tool (1). Both images are compared and optionally subtracted from each other. Defects imposed to the substrate due to contaminating particles only during the present processes with sizes larger than 10 mum are visible on the substrate image, while defects imposed earlier are diminished as well as structures formed from e.g. a mask pattern below 10 mum. Pattern recognition allows an efficient classification of the defects being just detected in a processing tool (1). Thus, semiconductor wafer yield and metrology capacity are advantageously increased.