Generalization of Yield Optimization Problem: Maximum Income Approach

An approach to statistical design centering (SDC) based on a simple generalization of the production yield concept is introduced, leading to a new figure of merit called the "income index." The measure can be considered as a simple model of the manufacturer\´s income or as a parameter characterizing the average quality of the manufacturing process. The income index takes into account the "price" (or "quality") decrease of inferior and the "price" (or "quality") increase of superior designs. The method is especially effective in improving quality of the designs characterized by large production yield. It can also handle the problems where the circuit specifications are negotiable or not exactly known, thus extending the area of SDC applications. For the implementation of the proposed method the existing gradient algorithms of yield optimization can be used after only minor modifications of gradient calculating subroutines and practically negligible additional computational costs.