A rule-based simulation approach to scheduling problem in semiconductor photolithography process

In this research, we consider a scheduling problem in photolithography process of semiconductor manufacturing. Generally, the photolithography process can be regarded as the most important processes since it may affect the fab productivity due to its various technological attributes. Physically, the photolithography equipment consists of three main parts: scanner, spinner, and developer, and it is designed to process different types of products as a machine for general purpose. However, in current semiconductor fab system, the same type of product is processed in order to reduce recipe change time incurred by changing masks in scanner module. So, in this study, the multi-product production case with different recipes is considered in photolithography process, and 4 different lot-wafer input methods are evaluated from makespan point of view.