ILLUMINATION CONTROL METHOD AND ILLUMINATION CONTROL DEVICE FOR PULSE LIGHT SOURCE USED IN ALIGNER

摘要

A pulse light source illumination control method which can reduce a difference between the energy of a pulse light measured before exposure and an actual energy. First, the average energy density of a pulse illuminating light (IL) which has a predetermined frequency and is oscillated from an excimer laser light source (16) on a wafer (W) is measured. Then the oscillation frequency of the excimer laser light source at the time of exposure of the wafer (W) is determined. If the determined oscillation frequency is different from the predetermined frequency, the energy of the pulse illuminating light (IL) is regulated.