Quality and Reliability Assurance Systems in IBM Semiconductor Manufacturing

Soon after semiconductor manufacturing began it was realized that classical process control techniques were needed for the control of quality, reliability, and yield. The discovery and control of yield, quality, and reliability detractors have been pursued continually by IBM manufacturing engineers ever since, and the resulting evolution of process control techniques has grown into a highly disciplined state. Inferential methods were added later to augment the classic techniques. This paper, in addition to providing a brief overview of semiconductor manufacturing control techniques and placing them into historical perspective, discusses a method of feed-forward control based on statistical distributions which is used in the VLSI FET memory device line. This is followed by a description of a process profile technique which is used in bipolar logic manufacturing. The importance of the system aspects in both techniques is emphasized.