Lithographic apparatus or method of operating a lithographic processing cell, lithographic apparatus and lithographic processing cell

摘要

Scheduling of tasks in a lithographic apparatus, track unit or lithocell is performed by maintaining a register of the state of the machine and a database of tasks performable by the machine, generating possible sequences of tasks based on pre- and post-conditions on the system state (rather than a precedence relation) and selecting a sequence from the generated sequences that meets a given beginning state of the machine and a desired end state. Embodiments of the invention also allow for automated recovery from exceptions.