| 摘要 |
PURPOSE:To make it possible to cope with the increase and inclination in irregularity steps of a substrate, curving of an image surface in an exposure optical system and the reduction in focal depth, by performing exposure under the state the substrate is vibrated at a minute amplitude in the direction of an optical axis all the time. CONSTITUTION:After a wafer 3 is positioned at specified coordinates with a stage 9, a shutter in a lighting device is opened. The pattern of a reticle 1 is exposed on the wafer 3. The wafer 3 is fixed on a sucking stage 4 with vacuum sucking. The sucking stage is fixed on the stage 9 through piezoelectric elements 5-1-5-3. Vibrating displacement is imparted by a piezoelectric-element driving control circuit 8 at a minute amplitude V. At this time, the positioning of the wafer in the direction of the optical axis is performed so that a gap DELTA between the surface of the wafer 3 and the end surface of a sensor becomes always constant. A voltage, which is varied with the output signal of a waveform generating circuit 10 with an applied voltage giving the specified gap DELTA as the center, is applied to the piezoelectric elements. Therefore, the wafer is vibrated at the displacement in the direction of the optical axis. When a shutter is opened by an exposure time Te under said vibrating state, the exposure is performed.
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