| 摘要 |
An exposure method for conducting exposure with high, uniform illuminance by illuminating light (IL) for exposure even when the illuminating light (IL) is a laser beam having a wavelength in the vacuum ultraviolet region. The illuminating light (IL) which is a linearly-polarized F2 laser beam emitted from a laser light source (1) passes through a prism (3), an oscillating mirror (4), bly-eye lenses (5A, 5B), and a condenser lens (9) and illuminates a reticle (R). The pattern on the reticle (R) is transferred onto a wafer (W) through a projection optical system (PL). The prism (3) is made of a crystal of magnesium fluoride (MgF2) which is a birefringent glass material transparent to the F2 laser beam. The prism (3) has a thickness gradually varying in the direction perpendicular to the optical axis of the illuminating light (IL) and is so disposed that it exhibits birefringence with respect to the illuminating light (IL). The polarized state of the illuminating light (IL) is continuously changed in a predetermined direction in a plane perpendicular to the optical axis. |
