Quality based scheduling for an example of semiconductor manufactory

Quality is an important measurement within a semiconductor manufactory. Due to the fact that yield is directly affected by quality of the manufacturing process, in this paper a quality based scheduling approach will be presented which compares different methods like dispatching, MIP and CP, regarding different objectives. To test the different used methods a benchmark model of a semiconductor manufactory is build up. Here a lithography work center is used in detail where the rest of the fabrication is only build up as a delay station. With this model the repeatability for the example of a lithography step is investigated. Thereby in this investigation it is assumed, that each lithography tool has an offset which is transferred to the structure. Now the quality of a product should be best, if the offset from one layer to the next layer is minimized.