AMHS design for reticles in photolithography area of an existing wafer fab: IE: Industrial engineering

In semiconductor manufacturing, most of 200mm fabrication facilities (called fabs) currently existing operate in manual or in semi-automatic material handling system. To remain competitive and to deal with the migration from high-volume/low-mix to high-mix/low-volume, most of these fabs require investment on factory automation especially on handling operations. This paper addresses a problem of Automated Material Handling System (AMHS) design for reticle in a photolithography area of 200mm wafer fab that was not originally designed to have such system. The objective is to define AMHS components: tracks layout, fleet size and management and reticle storing system while taking into account the existing area layout constraints (machine locations, storage area, corridors dimensions). A simulation approach is adopted to model the Automated Reticle Handling System (ARHS) and analyze the effect on key performance indicators. Using real instances, many simulation tests with alternative designs have been conducted which provided practical feedbacks.