Wafer Inspection System: Calibration and Measurement
Wafer surface scanners are widely used in semiconductor industries to detect particle contamination on wafers. The performance characteristics of a PMS SAS-3600 wafer surface scanner have been evaluated using ideal polystyrene latex (PSL). It was also used to measure irregularly shaped silicon particles. Three sizes of PSL spheres (0.199μm, 0.3μm, and 0.426μm) were used to study the sizing accuracy and counting efficiency of this wafer scanner. The results show that this scanner sizes 0.199μm and 0.3μm PSL reasonably accurate. But it cannot size 0.426μm PSL very well. The background noise lever was so high that this scanner could not measure particles near its nominal lower detection limit: 0.1μm. It over-counted Si particles by 28%. An electrostatic enhanced wafer deposition chamber was used to prepare the test wafers. Both the theoretical calculations and experimental results show that electrostatic force increases the deposition velocity by 2 orders of magnitudes for particles smaller than 1μm. The sedimentation is the dominant mechanism for particles larger than 1μm.
Sizing Accuracy, Counting Efficiency, Lower Detection Limit and Repeatability of a Wafer Surface Scanner for Ideal and Real‐World Particles
The performance characteristics of a Tencor Surfscan 4000 wafer surface scanner have been evaluated using ideal polystyrene latex (PSL) spheres and irregularly shaped real-world particles of Si and SiO 2 . The particles were uniform in size and were deposited on bare silicon wafers and used as standard calibration wafers to study the scanner response. Particles in the 0.1 to 1.0 μm diam range were used. The sizing accuracy, counting efficiency, lower detection limit, and count repeatability of the scanner were studied systematically. The full Maxwell's electromagnetic equations also have been solved numerically on a supercomputer to obtain the light-scattering cross section of the particles on bare silicon wafers
Medieval Modal Theories and Modal Logic Handbook of the History of Logic. Volume 2: Mediaeval and Renaissance Logic
1The translation of the Categories is edited by L. Minio-Paluello in Aristoteles Latinus 1.1-5 (Bruges-Paris: Descl~e de Brouwer, 1961) and the translation of the De interpretatione by L. Minio-Paluello in Aristoteles Latinus II.1-2 (Bruges-Paris: Descl~e de Brouwer, 1965). The translation of Porphyry's Isagoge is edited by L. Minio-Paluello and B.G. Dod in Aristoteles Latinus 1.6-7 (Bruges-Paris: Descl~e de Brouwer, 1966). Boethius's commentary on Aristotle's Categories is found in Patrologia Latina (ed. J.-P. Migne), 64, 159-294, De syllogismis categoricis in Patrologia Latina 64, 793-832, In Ciceronis Topica in Patrologia Latina 64, 1039-1169; an English translation with notes and an introduction by E. Stump, and De differentiis topicis in Patrologia Latina 64, 1174-1216; an English translation with notes and essays by E. Stump, Boethius's De topicis differentiis (Ithaca and London: Cornell University Press, 1978), Boethius's In Ciceronis Topica (Ithaca and London: Cornell University Press, 1988). Boethius's two commentaries on De interpretatione are edited by C. Meiser (Leipzig: Teubner, 1877-1880), his two commentaries on Porphyry's Isagoge by S. Brandt, Corpus Scriptorum Ecclesiasticorum Latinorum 48 (Leipzig: G. Freytag, Vienna: F.Tempsky, 1906), De hypotheticis syllogismis by L. Obertello (Brescia: Paideia, 1969) and De divisione by J. Magee, with a translation and commentary (Leiden: Brill, 1998). Some other ancient works were also used, such as Apuleius's Peri hermeneias (ed. C. Moreschini in Opera III (Stuttgart: Teubner, 1991), Augustine's Dialectica, trans, with notes by B.D. Jackson from the text edited by J. Pinborg, Synthese Historical Library 16 (Dordrecht: Reidel, 1975), and pseudo-Augustinean De decern categoriis, ed. L. Minio-Paluello, in Aristoteles Latinus 1.1-5, 133-75. For the sources of eleventh and twelfth century logic, see J. Marenbon, 'Medieval Latin Commentaries and Glosses on Aristotelian Logical Texts, Before c. 1150 AD' in Ch. Burnett (ed.), Glosses and Commentaries on Aristotelian Logical Tezts (Warburg Institute Surveys and Texts 23), (London: Warburg Institute, 1993), 77-127, republished and revised in J. Marenbon, Aristotelian Logic, Platonism, and the Contezt of Early Medieval Philosophy in the West, Variorum Collected Studies Series (Aldershot: Ashgate, 2000). 2Analytica priora, ed. L. Minio-Paluello, Aristoteles Latinus III.l-4 (Bruges-Paris: Descl~e de Brouwer, 1962), Analytica posteriora, ed. L. Minio-Paluello and B.G. Dod, Aristoteles Latinns IV.l-4 (Bruges-Paris: Descl~e de Brouwer, 1968), Topica, ed. L. Minio-Paluello and B.G.