COST-DRIVEN PARAMETER DESIGN

Parameter design methodology has focused primarily on the quadratic lo ss function, which can often be solved by using a two-step procedure i nvolving the minimization of a dispersion measure and then adjusting t he mean to target. In some practical situations, however, the loss can be nonquadratic or highly skewed. By building on a theory of Leon and Wu, we develop a modeling and data-analysis strategy for a general lo ss function, in which the quality characteristic follows a location-sc ale model. The only difference from the two-step procedure just mentio ned is the adjustment step, in which the mean is moved to that side of the target with lower cost. The technique is illustrated on an experi ment involving epitaxial-layer growth in integrated-circuit fabricatio n.