SINGLE-WAFER CLUSTER TOOL PERFORMANCE - AN ANALYSIS OF THE EFFECTS OFREDUNDANT CHAMBERS AND REVISITATION SEQUENCES ON THROUGHPUT

Recent trends in the semiconductor industry indicate the need to explo re alternatives to batch-wafer manufacturing, One proposed alternative is a micro-factory based on cluster tools, This paper presents an ana lysis of the effect of redundant chambers and chamber revisitation pro cess sequences on the throughput in an individual cluster tool, Theore tical models which quantify the time required to process a lot of wafe rs in a cluster tool are developed for these situations, The differenc es between scheduling algorithms which use the load-lock as a queue an d those that do not are also explored, Finally, the models developed i n the work are integrated into a model which bounds the minimum theore tical turn-around-time which can be achieved in a cluster based fab.