| 摘要 |
PROBLEM TO BE SOLVED: To provide a substrate holding system which supplies a vacuum to hold a semiconductor wafer even if a power supply of a vacuum pump is suddenly broken down, and never complicates and increases a size of the entire equipment. SOLUTION: The substrate holding system comprises a substrate holding mechanism 402, 404, and 406 for holding a substrate by vacuum suction, vacuum pump 100 for supplying a vacuum to the substrate holding mechanism 402, 404, and 406, power supply for supplying driving power of the vacuum pump 100, vacuum ejector 200 for generating a vacuum from the air supplied from outside, and vacuum source switching means 300 and 302 which switches a vacuum source for supplying a vacuum to the substrate holding mechanism 402, 404, and 406 between the vacuum pump 100 and the vacuum ejector 200, with the vacuum pump 100 selected when the output of the power supply is normal, and the vacuum ejector 200 selected when there is something wrong with the output of the power supply. COPYRIGHT: (C)2004,JPO&NCIPI |
