Cost effective reticle quality management strategies in wafer fabs

A statistically based methodology has been developed to plan and/or optimize the use of reticle inspection capacity in the fab. Statistical methods are used to analyze reticle and product data which are combined, in a stochastic model, with financial parameters. The model uses the combined information to calculate the cost of different reticle inspection strategies, allowing both capacity planning and allocation optimization of given inspection capacity. In this paper we present the reticle inspection planning problem, our solution methodology, excerpts of data analysis performed, and an example inspection planning calculation.