Print Email Facebook Twitter Increased particle inspection sensitivity by reduction of background scatter variance Title Increased particle inspection sensitivity by reduction of background scatter variance Author van der Walle, P. Kumar, P. Ityaksov, D. Versluis, R. Maas, D.J. Kievit, O. Janssen, O. van der Donck, J.C.J. Publication year 2013 Abstract In dark-field particle inspection, the limiting factor for sensitivity is the amount of background scatter due to substrate roughness. This scatter forms a speckle pattern and shows an intensity distribution with a long tail. To reduce false-positives to an acceptable level, a high detection threshold should be chosen such that the tail of the background distribution is avoided. We have modeled an optimized illumination mode, that reduces the variance in the background distribution. This illumination mode illuminates the substrate from multiple azimuth angles. We show that the speckle patterns generated by each azimuth angle can be independent from each other. Therefore by combining the angles, the variance of the background signal is reduced. We show that for the parameters of our inspection system the detection threshold can be reduced by a factor three, resulting in a lower detection limit that is 20% smaller in particle size. The change in the background scattering distribution was confirmed by experiments. © 2013 SPIE. Subject Physics & ElectronicsNI - Nano InstrumentationTS - Technical SciencesHigh Tech Systems & MaterialsElectronicsIndustrial InnovationDark-field microscopyDetection limitEUVLIlluminationParticle inspectionQualificationRapid NanoSpeckle To reference this document use: http://resolver.tudelft.nl/uuid:9bb28268-fd80-4db6-b965-e2540f5e636e TNO identifier 473181 ISBN 9780819494634 ISSN 0277-786X Source 27th Conference on Metrology, Inspection, and Process Control for Microlithography, 25-28 February 2013, San Jose, CA, USA, 8681 Series Proceedings of SPIE - The International Society for Optical Engineering Article number 868116 Document type conference paper Files To receive the publication files, please send an e-mail request to TNO Library.