A study on the spine layout for semiconductor manufacturing facility using simulated annealing

Abstract

The construction cost for the wafer fab. of a semiconductor manufacturing is about NT$ 50 to 70 billions. Owing to the higher reentrant characteristics of the manufacturing process routing, the Automated Material Handling System (AMHS) and the layouts of the manufacturing fab. will determine the manufacturing efficiency at the earlier planning stage. The current wafer fab. layouts are their basis on the spine layout concepts. The spine layout is to allocate the material handling system at the center (like the spine of human body) of the manufacturing facilities, with the rest of the bays assigned to areas along the spine. This layout can reduce the material handling distance (time) and decrease the collision and vibration of the material handling systems. The benefits of this concept can utilize the modularized function area to form the desired construction for use. A bay configuration arranged along a central spine and served by an AMHS is common for the layout and material handling system in the semiconductor wafer fabrication facilities. The purpose of adapting AMHS is to seek the best layout with low transportation cost and an efficient flow to reduce shock and vibration during the material handling, and the best use of manufacturing resources. This paper applies the simulated annealing algorithm to the problem of spine layout, and considers four different material flow directions (clockwise, round way, clockwise with a short cut, and round way with a short cut) in the design process. The material handling cost and time are two evaluation criteria for this problem. Experiments were conducted to investigate the control parameters of the simulated annealing process so that the best solution and time can be found. The results show that the flow directions, cooling rate (r) and replicates (L) are significant factors.