Abstract: A scheduler handles the various tasks to be performed on a wafer processing system as operations, with each operation having a predefined data structure. Operations that meet a set of requirements are added to an operation list. In the operation list, operations meeting another set of requirements are switched to the active state. Each active operation in the operation list is scheduled to run on the wafer processing system. Using structured operations to perform various tasks improves the extensibility and maintainability of the present scheduler. Further, the present scheduler can schedule several compatible operations at the same time by going through each operation in the operation list, and running those that are in the active state.

Abstract: Each module of a wafer processing system is given a classification. Upon receipt of a command to move the wafer to one of the modules, a sequence enumerating the modules to be visited by the wafer before reaching its destination is created. The modules are added to the sequence based on their classification. The wafer is then worked on in each module enumerated in the sequence. By creating the sequence when needed, the number of static files that have to be maintained and stored in the wafer processing system is minimized. Further, creating the sequence at the time it is needed allows the sequence to take advantage of the history of the wafer and thereby eliminate unnecessary steps.

Abstract: Each module of a wafer processing system is given a classification. Upon receipt of a command to move the wafer to one of the modules, a sequence enumerating the modules to be visited by the wafer before reaching its destination is created. The modules are added to the sequence based on their classification. The wafer is then worked on in each module enumerated in the sequence. By creating the sequence when needed, the number of static files that have to be maintained and stored in the wafer processing system is minimized. Further, creating the sequence at the time it is needed allows the sequence to take advantage of the history of the wafer and thereby eliminate unnecessary steps.