SIMULTANEOUS CONTROL OF MULTIPLE MEASURES OF NONUNIFORMITY USING SITEMODELS AND MONITOR WAFER CONTROL

Present day semiconductor manufacturing processes are subject to tight specifications, High yields with tight process specifications require drive to target process control, As the size of the wafer in the semi conductor industry increases, nonuniformity across the wafer becomes a crucial yield limiting issue, Modeling nonuniformity in terms of the equipment settings permits calculation of recipes required to achieve the desired nonuniformity, However, models for single measures of nonu niformity, such as standard deviation, or range, do not capture all as pects of the nonuniformity and often do not model well in terms of the equipment settings, This paper describes the use of spatial models to simultaneously quantify multiple measures of nonuniformity, and a con troller to keep the nonuniformities within specifications, Use of spat ial models in conjunction with a monitor wafer controller (MWC) enable s the simultaneous control of multiple nonuniformity measures, The pap er presents the results of applying the MWC with spatial models to a p lasma enhanced TEOS (PETEOS) deposition process on an Applied Material s Precision 5000 (AMT5000), The controller has been keeping the PETEOS process within specifications for over two years.