## 1 Introduction  
As semiconductor processes continue to be refined, the requirements for the equipment used in semiconductor manufacturing are becoming increasingly demanding. Since even fine particles can directly cause defects in semiconductors, various efforts have been made to reduce particle contamination. The main factors contributing to particle generation in wafer transport systems can be summarized as linear motion (LM) guides, belts, cables, cable bays, and lubrication [1, 2]. In other words, particle generation in the wafer transport system is caused by friction, abrasion, and lubrication. Particle generation cannot be completely eliminated with contact-based transport systems. Therefore, interest in high-clean transfer systems is increasing in the field of ultra-fine semiconductor manufacturing. Recently, in semiconductor manufacturing processes, the development of contactless delivery systems has been actively developed due to the importance of particle-free and highly accurate delivery operations [3, 4, 5, 6]. Magnetic levitation technology is considered a highly promising alternative to meet these requirements [7]. Magnetic levitation eliminates contact in the conveying system, minimizing friction, wear, and particle generation. It can also operate stably in a vacuum environment, making it suitable for various semiconductor manufacturing processes [8]. In a study by [PERSON] et al. [9], experiments were conducted to measure the contamination of dust particles during wafer delivery in a vacuum environment. The results showed that the magnetic levitation transport system is highly beneficial for particle-free transportation and exhibits very low outgassing. Conventional research on magnetic levitation equipment has focused on implementing stages with levitation masses within several kilograms to achieve exceptional motion control accuracy [10; 11; 12; 13]. These advanced magnetic levitation stages hold significant promise for critical semiconductor manufacturing processes, such as photolithography, which demand nanometer-level precision [14; 15]. Recently, there have been notable developments in the field, including a high-precision magnetic levitation transfer system capable of enabling long-stroke movements and transporting movers weighing more than hundreds of kilograms [16; 17]. Moreover, researchers are exploring various configurations for magnetic levitation transport systems, such as attaching electromagnets and linear propulsion motors to the moving part or fixed rails [18; 19; 20]. Additionally, real-scale prototypes are being developed to experimentally validate the effectiveness of proposed methods. These efforts aim to further enhance the capabilities and applications of magnetic levitation technology in the semiconductor manufacturing industry. In this study, magnetic levitation was applied to a wafer transport system by replacing the roller and LM guide. A multi-joint wafer handling robot was installed at the top of the wafer transfer system, and this robot performed precise work, enabling rapid and accurate transfer even under harsh working conditions with extremely high acceleration and deceleration. To ensure control performance even under these challenging operational conditions, a robust controller has been designed based on loop shaping method. Therefore, a controller that precisely controls the five degrees of freedom (5-DOF) of the wafer transfer system was designed to enable high-speed transfer and precise position control by replacing wheels with magnetic levitation modules installed at the four corners. In addition, the stability and reliability of the magnetic levitation was experimentally verified to confirm its applicability in the actual manufacturing environment with a real-scale prototype of a wafer transfer system. This paper is organized as follows. In Section 2, the system configuration of a magnetic levitation wafer transfer system is presented.