SIMULATION OF YIELD COST LEARNING-CURVES WITH Y4/

This paper describes a prototype of a discrete event simulator-Y4 (yie ld Forecaster)-capable of simulating defect related yield loss and man ufacturing cost as a function of time, for a multiproduct IC manufactu ring line, The methodology of estimating yield and cost is based on mi micking the operation and characteristics of a manufacturing line in t he time domain, The paper presents a set of models that take into acco unt the effect of particles introduced during wafer processing as well as changes in their densities due to process improvements, These mode ls also illustrate a possible way of accounting for the primary attrib utes of fabrication, product, and failure analysis which affect yield learning, A spectrum of results are presented for a manufacturing scen ario to demonstrate the usefulness of the simulator in formulating IC manufacturing strategies.