METHOD AND APPARATUS FOR DISTINGUISHING BETWEEN SOURCES OF PROCESS VARIATION

A method for distinguishing between sources of process variation includes processing a plurality of manufactured items in a process flow; storing a set of production environment data associated with each of the manufactured items; identifying manufactured items associated with a process drift; generating a plurality of characteristic threads based on the production environment data; comparing the characteristic threads for at least those manufactured items associated with the process drift; and determining at least one potential cause for the process drift based on the comparison of the characteristic threads. A manufacturing system for distinguishing between sources of process variation is also provided. The manufacturing system includes a plurality of tools for processing manufactured items in a process flow, a database server, and a drift monitor.