Patent ID: 8271122

Claim:
A method for monitoring a manufacturing tool used in a manufacturing process, comprising: a. acquiring metrology data for semiconductor wafers at the conclusion of a final process step for the manufacturing process; b. acquiring data for a plurality of process variables for a first process step performed by the manufacturing tool for manufacturing semiconductor wafers; c. creating a first mathematical model of the first process step performed by the manufacturing tool based on the metrology data and the acquired data for the plurality of process variables for the first process step performed by the manufacturing tool; d. repeating step b. and step c. for at least a second process step performed by the manufacturing tool for manufacturing the semiconductor wafers; e. creating an n th mathematical model based on the metrology data and the data for the plurality of process variables for each of the n process steps; f. creating a top-level mathematical model based on the metrology data and the models created by steps c., d. and e.; g. calculating a multivariate metric based on the top-level model of step f. and data for the plurality of process variables for at least one of the process steps performed by the manufacturing tool during subsequent runs of the manufacturing tool; and h. servicing the manufacturing tool if the calculated multivariate metric satisfies a predetermined condition.