Resident-entity based simulation of batch chamber tools in 300 mm semiconductor manufacturing

We describe a resident-entity based pilot simulation study of a class of tools used in 300 mm semiconductor manufacturing known as the wets tools or the wet benches. These are batch chamber tools - they have several chambers or tanks, each of which can accommodate a batch of wafers, usually more than one lot size. We develop a simulation model for the wets processing area that is based on the resident-entity paradigm, but makes use of transient-entity-type modeling when more information needs to be tracked. Resident-entity models tend to be much faster than transient-entity simulation models that are common in semiconductor manufacturing. The model developed captures most of the internal workings of a wets tool and at the same time, models different types of tools. We used the model to evaluate the effects of scheduling policies and batching parameters on the performance of the wets process area.