OPTIMIZATION VERSUS CONSTRUCTION OF TRANSPORT SCHEDULES TO REDUCE TRAVEL TIME VARIABILITY AND AVOID CONGESTIONS IN CONVEYOR-BASED AMHS FOR WAFER FABS

Advanced transport scheduling for conveyor-based automated material handling systems (AMHS) in semiconductor fabricating facilities (wafer fabs) can reduce transport times and thus cycle times. Commonly, transport operations of arriving wafer lots at conveyor junctions, such as rotary tables, are sequenced ad-hoc by myopic first-come-first-serve policies. In contrast, improved transport schedules for the transport operations can be produced ahead of the time in conjunction with the overall production schedule for process operations. More precisely, such a transport schedule can either be sequentially constructed by fixing one transport after another, or it can be optimized by simultaneously fixing several conflicting transports. Hence, two conceptually different transport scheduling methods, which both avoid congestions by enforcing a no-wait constraint, are compared with special regard to transport-related variability. Furthermore, three different AMHS models that exhibit the typical interbay-intrabay layout are used for computational experiments.

[1]  Thomas Arzt,et al.  1 A NEW LOW COST APPROACH IN 200 MM AND 300 MM AMHS , 1999 .

[2]  Reha Uzsoy,et al.  Hybrid decomposition heuristics for solving large-scale scheduling problems in semiconductor wafer fabrication , 2007, J. Sched..

[3]  Jairo R. Montoya-Torres,et al.  A literature survey on the design approaches and operational issues of automated wafer-transport systems for wafer fabs , 2006 .

[4]  C. H. Chen,et al.  Optimization of AMHS design for a semiconductor foundry fab by using simulation modeling , 2013, 2013 Winter Simulations Conference (WSC).

[5]  Lars Mönch,et al.  An integrated scheduling and material-handling approach for complex job shops: a computational study , 2012 .

[6]  Reha Uzsoy,et al.  Decomposition Methods for Complex Factory Scheduling Problems , 1996 .

[7]  D Nazzal,et al.  An Analytical Model for Conveyor-Based Material Handling System With Crossovers in Semiconductor Wafer Fabs , 2010, IEEE Transactions on Semiconductor Manufacturing.

[8]  G.K. Agrawal,et al.  A survey of automated material handling systems in 300-mm SemiconductorFabs , 2006, IEEE Transactions on Semiconductor Manufacturing.

[9]  Cecilia Temponi,et al.  Critical Variables in the Decision-Making Process for AMHS Technology Selection in Semiconductor Wafer Size Transitions: Exploratory Study , 2012, IEEE Transactions on Semiconductor Manufacturing.

[10]  John W. Fowler,et al.  A survey of problems, solution techniques, and future challenges in scheduling semiconductor manufacturing operations , 2011, J. Sched..

[11]  Klaus Kabitzsch,et al.  Continuous flow transport scheduling for conveyor-based AMHS in wafer fabs , 2017, 2017 Winter Simulation Conference (WSC).

[12]  Oliver Rose,et al.  Implementation of a simulation-based short-term lot arrival forecast in a mature 200mm semiconductor FAB , 2011, Proceedings of the 2011 Winter Simulation Conference (WSC).