Modeling the performance of cluster-based fabs

The economic performance of cluster tools is evaluated by modeling a hypothetical cluster-based fab, where almost all of a 0.6-μm DRAM (dynamic random-access memory) process flow is performed in cluster tools. A conventional fab under the same cost constraint running the same flow is also modeled as a base for comparison. From this model, a number of inherent differences between cluster-based fabs and conventional fabs are observed and described. Monte Carlo cost-based simulations are then run on the two fabs to compare the potential cost and throughput time performance of the fabs. Results suggest that the cluster-based fab can operate at considerably reduced throughput times for a relatively small cost per wafer premium. Modeling the cluster-based fab revealed a number of fab design and management issues that are much less significant or nonexistent for conventional fabs. These issues include configuration and scheduling, lot size, and scaling the fab