Design of Partially High-Temperature Superconducting Planar Motor for Semiconductor Optical Lithography

Superconducting motors should further be improved in their performance to realize high-performance optical lithographic machines to meet the huge and growing demands for manufacturing integrated circuits (ICs) in the semiconductor industry. In this paper, a moving-coil coreless partially high-temperature superconducting (HTS) planar motor is proposed to satisfy such demands. The proposed motor has both the stator and the mover inside a cryostat, which are cooled by a single-stage GM cryocooler and a radiation heat transfer respectively, and the stator has direct current HTS coils made of rare-earth barium-copper-oxide (ReBCO) instead of permanent magnets. The design process of the proposed motor described involves the calculation of motor force, stator flux density, HTS coil current, HTS temperature, alternating current losses of superconductor, and a heat loss of cryostat. The designed motor is compared with the conventional motor, and the comparison shows that the proposed motor is superior to the conventional motor in terms of stage acceleration at the same superconductor temperatures from 20K to 40K, mover ohmic loss, and simple cooling of mover coils.