Use case approach to integrating and implementing lithography run-to-run control

The benefits of using a run-to-run control system for overlay and CD control have been well documented. However, before any these benefits can be achieved, one must first integrate the run-to-run control system into the existing automation and manufacturing execution system (MES) environment. Integration details that are overlooked during the planning stages often times create unnecessary challenges down the road that can delay reaching advantageous control results. INFICON has developed a novel methodology of documenting process and integration requirements. This method, termed Use Case Review, congregates the appropriate resources from the supplier and the customer to review and customize a predetermined set of documents that describe the run-to-run controller. Each use case contains a flow diagram and a detailed sequence of transactions documenting the actors (Automation PC, Process Equipment, MES, etc.) and variables (Lot ID, Process Level ID, Recipe ID, etc.) involved. The combined set of use cases covers all aspects of integrating a lithography run-to-run controller. During the implementation of NVS ARGUS(R), TOWER Semiconductor Ltd. benefited from use case review and customization.