| 摘要 |
PURPOSE:To enable execution of superposition exposure of high precision without stopping a wafer stage, by shaking the wafer stage and by executing the exposure by a pulse light emitted at the moment when an error in superposition of a reticle and the eater becomes zero. CONSTITUTION:An alignment mark in a water 16 set on a wafer stage 4 is measured and the stage 4 is moved to a regular position of exposure. A fine- motion X-Y stage 6 is driven when a stage stop position comes in an area of 1/4 or below of a diffraction grating pitch in relation to a target position, and thereby the wafer stage is shaken at about 200Hz. Next, a TTL alignment means 9 detects a positional deviation of a reticle 2 from the wafer 16 by using a Seeman laser 15 and generates a trigger signal 17 to make an excimer laser 1 emit a pulse light at the moment when a phase difference of a position detection signal in a uniaxial direction is zero. Since the stage 4 is not stopped, according to this constitution, a throughput is improved and also exposure can be executed with high precision in superposition. |
