Measuring process yield for nonlinear profiles

Assuring the process capability in nonlinear profiles to meet the requirement is a very important task. This paper aims at evaluating the process yield for nonlinear profiles in manufacturing processes. We present the statistical properties of the estimated S_pkA and obtain its lower confidence bound. This index provides an exact measure of the process yield for nonlinear profiles. A simulation study is conducted to assess the performance of the proposed method. The simulation results confirm that the estimated S_pkA value is close to the target value and has the smallest standard deviation. One real example is used to demonstrate the application of the proposed approach.