Semiconductor metrics: conflicting goals or increasing opportunities?

In order to improve semiconductor manufacturing performance, companies typically utilize various metrics such as cycle time, throughput and yield. By tracking the progress of one or more of these metrics and setting achievement goals, many companies are able to make significant metric improvements. However, metric improvement is only beneficial if it results in actual manufacturing improvement. Metrics may be influenced by forces outside manufacturing, they may conflict with other metrics, or they may actually increase undesirable outcomes in the fab. This paper highlights some of the current problems with metric utilization in semiconductor fabs. Examples from industry and results using data from the Competitive Semiconductor Manufacturing Study at the University of California at Berkeley are given. We present some practical solutions, highlighting the Overall Equipment Effectiveness Teams at Texas Instruments which have been designed to minimize many of the semiconductor metric problems.