| 摘要 |
PURPOSE:To realize a reducing projection aligner wherein an optical axis is stabilized; high-precision position and length measurement is possible, and microminiaturization and massproduction are properly made by separating and shielding a length measuring part and a wafer stage part from the circumferential atmosphere of the other part positions, and installing a jetting outlet and sucking inlet on the inner upper pat and the inner lower part, respectively. CONSTITUTION:The peripheral part between an upper base 3 and a lower base 4 is separated from the air flow blown out from a clean chamber 1 with a shielding plate 5. An air jetting outlet 8 is installed at the lower part of the upper base 3. An air sucking inlet 9 is installed at the upper part of the lower base 4. The air blown out from the air jetting outlet 8 is subjected to down-flow, sucked by the sucking inlet 9, made to pass an air circulating route 11 of the clean chamber 1, sent by a blower 13, cleaned by a filter 12, and circulated. As a result, the generation of turbulence caused by the movement of a wafer stage is restrained, and an optical axis path is stably maintained. As to the turbulence caused by the down-flow in the inside the vertical distance is reduced, and the sucking force is increased, thereby being minimized. Hence foreign matter such as oil mist generated from the wafer stage can be discharged. |
