Improving uptime of clustered lithography tools by smart maintenance

For lithography cluster tools a very high uptime and utilization are essential. Maintenance time, i.e. scheduled downtime has to be minimized. After a maintenance a lithography cluster tool has to be requalified before being put back into production. To date the results of the test wafer measurements are evaluated by the maintenance staff. In this paper we present a software solution which establishes an interface between the maintenance manager software and the statistical process control software, so that the requalification process is automized entirely. As no human assistance is required for the requalification procedure, the lithography tool may be put back into production immediately after the test wafer measurement has been completed, without any machine uptime loss due to human reaction time.