Patent ID: 8660681

Claim:
A method of monitoring a lithography process flow in a manufacturing environment, the method comprising: receiving a first plurality of parameter values by a monitoring system operatively connected to said manufacturing environment, each of said first plurality of parameter values indicating an exposure state parameter in a first type of lithography process of said process flow when processing a first plurality of substrates; receiving a first plurality of measurement results by said monitoring system, each one of said first plurality of measurement results being associated with a respective one of said first plurality of parameter values; comparing, by said monitoring system, a first global value obtained from each of said first plurality of parameter values and each of said first plurality of measurement results and a variance thereof with a first local value obtained from a subset of said first plurality of parameter values and a subset of said first plurality of measurement results and said variance, said subset of said first plurality of measurement results being associated with said subset of said first plurality of parameter values; and outputting an out-of-control signal by said monitoring system when a result of said comparison is outside of a predefined valid range.