Method and apparatus for using tool state information to identify faulty wafers

摘要

A method for identifying faulty wafers includes processing a set of wafers in a tool; collecting tool state information during the processing of the set of wafers; generating a tool state information baseline; comparing the tool state information for each wafer to the tool state information baseline to identify any wafers with outlying tool state information; and designating a particular wafer in the set as suspect in response to identifying outlying tool state information for the particular wafer. A processing line includes a tool adapted to process a set of wafers, and a process controller. The process controller is adapted to collect tool state information during the processing of the set of wafers, generate a tool state information baseline, compare the tool state information for each wafer to the baseline tool state information to identify any wafers with outlying tool state information, and designate a particular wafer in the set as suspect in response to identifying outlying tool state information for the particular wafer.