Patent ID: 8380472

Claim:
A yield management apparatus, comprising: means for receiving at least one case describing a semiconductor fabrication process, where a case comprises at least one prediction variable and at least one response variable corresponding to the at least one prediction variable; means for identifying, based at least in part on the at least one prediction variable, a number of times that a tool is used during the semiconductor fabrication process; means for producing at least one additional variable for the at least one case, the additional variable having a value equal to the identified number of times that the tool is used in the semiconductor fabrication process; means for generating a processed data set by adding the at least one additional variable to the at least one case; means for generating a model based on the processed data set, where the model describes the relationship between the at least one prediction variable, the at least one additional variable and the corresponding at least one response variable for the semiconductor fabrication process, the model is a decision tree, and the decision tree is tiered split using at least a first prediction variable of the at least one prediction variable; means for analyzing the generated model to identify at least one factor that affected a yield of the semiconductor fabrication process, where the at least one factor is identified out of the at least one prediction variable; and means for outputting the at least one factor that affected the yield of the semiconductor fabrication process.