A Scanner Throughput Monitoring System (STMS) for continuously improving litho-cluster productivity

The litho-cluster is the main manufacturing equipment in a semiconductor Fab. Manufacturers have difficulty in clarifying the root cause of productivity variation within the litho-cluster because of various factors in determining the productivity and the complex wafer motion system. Hence, the “Scanner Throughput Monitoring System” (STMS) was developed by UMC in order to monitor the productivity variations, quickly identify the possible causes of the bottleneck, and take the corresponding actions to improve productivity.