Utilizing simulation to develop economic equipment selection and sampling plans for integrated circuit manufacturing

This article presents a Monte Carlo simulation model for designing and selecting integrated circuit (IC) inspection systems and equipment choices. It briefly describes the processes and types of inspections used in the manufacture of ICs. The effects of defect characteristics (e.g. size and density) and equipment defect detection rates (e.g. objective lens power) are studied as determinants of the optimal inspection configuration. As shown by the simulation model, the faster, more accurate, and more costly automated systems may be unnecessary depending on defect characteristics. The annual total costs differences, and thus achievable savings, between the several possible detection systems are shown to vary by $500,000 or more depending on process defect densities.