Patent ID: 11868119
Assignee: TOKYO ELECTRON LIMITED
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 4:
5. A method of characterizing a fabrication process for manufacturing a semiconductor wafer, the fabrication process comprising a plurality of process steps, at least a first one of the plurality of process steps being associated with a plurality of process variables, the method comprising:
performing a design of experiment process, the design of experiment process comprising:
for a series of design of experiment semiconductor wafers, performing the first one of the plurality of process steps on the series of design of experiment semiconductor wafers, wherein at least one or more of values of the plurality of process variables are changed for each of the series of design of experiment semiconductor wafers;
obtaining design of experiment wafer measurements of a first characteristic from the series of design of experiment semiconductor wafers wherein each of the design of experiment wafer measurements is associated with a spatial location on a design of experiment semiconductor wafer from which the design of experiment wafer measurement is obtained;
creating a design of experiment process step fingerprint from the obtained design of experiment wafer measurements for each of the series of design of experiment semiconductor wafers to provide a plurality of design of experiment process step fingerprints; and
creating a process model of the first one of the plurality of process steps utilizing the plurality of design of experiment process step fingerprints;

performing the first one of the plurality of process steps on at least one production semiconductor wafer;
obtaining production wafer measurements of the first characteristic of the at least one production semiconductor wafer wherein each of the production wafer measurements is associated with a spatial location on the at least one production semiconductor wafer from which the production wafer measurement is obtained;
creating a production wafer process step fingerprint from the obtained production wafer measurements;
calculating a modeled fingerprint for the production semiconductor wafer utilizing the process model of the first one of the plurality of process steps;
calculating a difference between the modeled fingerprint and the production wafer process step fingerprint; and
detecting a faulty process variable utilizing the calculated difference between the modeled fingerprint and the production wafer process step fingerprint.