Inspection method and apparatus, lithographic apparatus, lithographic processing cell and device manufacturing method

摘要

A fault detection and classification method is disclosed that uses raw back-focal-plane image data of radiation from a substrate surface, detected by a scatterometer detector, to determine a variation in the raw data and correlate the variation in the raw data with a possible fault in a lithographic apparatus or a process that patterned the substrate surface. The correlation is carried out by comparing the variation in the raw data with known metrology data. Once a fault has been determined, a user may be notified of the fault.