A REAL-TIME SCHEDULING AND RESCHEDULING SYSTEM BASED ON RFID FOR SEMICONDUCTOR FOUNDRY FABS

Abstract

This paper constructs a real-time scheduling and rescheduling system based on RFID (Radio Frequency Identification) information for fully automated fabs. The system consists of three modules: a real-time decision-making scheduler, a rescheduling mechanism for machine breakdowns and bottleneck, and a simulation platform. The proposed scheduling and rescheduling system have been successfully applied to the 300mm foundry fab of SEMATECH (SEmiconductor MAnufacturing TECHnology) and TRC fab (Hewlett-Packard Technology Research Center Silicon fab). From simulation results, the dispatching rule sets proposed by SVM scheduler have better performance than a single dispatching rule. In SEMATECH model, the mean flow time is reduced 3%(203.32→197.307 hours), tardy numbers are decreased 17% (63→52 lots), and throughput is increased (176852→177951 wafers). In TRC fab model, the mean flow time is reduced 4% (451.23→427.86 hours) and tardy numbers are decreased 25% (15→12 lots). Clearly, the results are much better than previous researches. In addition, the proposed framework can deal with the machine breakdowns and bottleneck so that the system performance can be improved in time.