Alex Ka Tim Poon

High Accuracy and High Capacity Motor Cooling System Using Phase Change of Refrigerant for Semiconductor Lithography Apparatus

As the requirement for the line width of semiconductor devices shrinks and the requirement for throughput of lithography exposure apparatus increases, a cooling system having higher accuracy as well as larger capacity is required in lithography exposure apparatuses. For this reason, the removal of heat generated by a linear motor, which is the major heat source in a lithography exposure apparatus, has become an important subject. This paper presents a method to accurately control the temperature of the motor using phase change of a refrigerant. Tests were conducted on a prototype motor using two-phase cooling system for uniform and varying heat loads upto 460 Watts. Results show that this system has the capability to remove a large amount of heat from the coils while maintaining uniform temperature across the motor with high accuracy.