Abstract
In this paper, a colored timed resource-oriented Petri net (CTROPN) is developed to model the cluster tools in semiconductor fabrication. It is structurally simple and concise, since each module in a cluster tool corresponds to a unique place in CTROPN. It is also powerful in modeling the qualitative and temporal behavior of the cluster tools with a single-blade or dual-blade robot. The initial transient behavior, steady-state behavior and the final transient behavior can all be investigated through a single model.