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dc.contributor.advisorFlake, Robert H.en
dc.contributor.advisorEdgar, Thomas F.en
dc.creatorPatwardhan, Ninad Narendraen
dc.date.accessioned2011-02-14T20:44:26Zen
dc.date.accessioned2011-02-14T20:44:40Zen
dc.date.available2011-02-14T20:44:26Zen
dc.date.available2011-02-14T20:44:40Zen
dc.date.issued2010-12en
dc.date.submittedDecember 2010en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2010-12-2097en
dc.descriptiontexten
dc.description.abstractIn the recent years threaded run-to-run (RtR) control algorithms have experienced drawbacks under certain circumstances, one such trait is when applied to high-mix of products such as in Application Specific Integrated Circuits (ASIC) foundries. The variations in the process are a function of the product being manufactured as well as the tool being used. The presence of semiconductor layers increases the number of times the lithography process must be repeated. Successive layers having different patterns must be exposed using different reticles/masks in order to maximize tool utilizations. The objectives of this research are to develop a set of methodologies for evaluation and extension of threaded control applied to overlay. This project defines methods to quantify the efficacy of threaded controls, finds the drawbacks of threaded control under production of high mix of semiconductors and suggests extensions and alternatives to improve threaded control. To evaluate the performance of threaded control, extensive simulations were performed in MATLAB. The effects of noise, disturbances, sampling and delays on the control and estimation performance of threaded controller were studied through these simulations. Based on the results obtained, several ideas to extend threaded control by reducing overall number of threads, by improving thread definitions and combination have been introduced. A unique idea of sampling the measurements dynamically based on the estimation accuracy is also presented. Future work includes implementing the extensions to threaded control suggested in this work in real production data and comparing the results without the use of those methods. Future work also includes building new alternatives to threaded control.en
dc.format.mimetypeapplication/pdfen
dc.language.isoengen
dc.subjectThreaded controlen
dc.subjectEWMAen
dc.subjectDisturbanceen
dc.subjectNoiseen
dc.subjectEstimationen
dc.subjectMSEen
dc.subjectLithographyen
dc.subjectOverlayen
dc.subjectRtRen
dc.subjectHigh-mixen
dc.subjectSemiconductor manufacturingen
dc.subjectProcess controlen
dc.titleEvaluation and extension of threaded control for high-mix semiconductor manufacturingen
dc.date.updated2011-02-14T20:44:40Zen
dc.description.departmentElectrical and Computer Engineeringen
dc.type.genrethesisen
thesis.degree.departmentElectrical and Computer Engineeringen
thesis.degree.disciplineElectrical and Computer Engineeringen
thesis.degree.grantorUniversity of Texas at Austinen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Science in Engineeringen


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