Yield learning and the sources of profitability in semiconductor manufacturing and process development

A numerical model that identifies the high-leverage variables associated with profitability in semiconductor manufacturing is presented. Varying the parameters of the model demonstrates that a rapid yield-learning rate determines profitability more than any other factor does. Factors such as ramping up early, adding fab capacity, depressing the terminal fault density, and shrinking die size all yield diminishing returns. The model also suggests that preparations in the early stages of process development are the key to successful yield learning.