| 摘要 |
PROBLEM TO BE SOLVED: To improve the uniformity of a rectangular illumination field by dynamically controlling the illumination field, providing desired exposure, controlling and reducing line width fluctuation in a local part. SOLUTION: Illumination energy is controlled by moving push rods 34 and selectively moving blades 48 into illumination energy or optical flux. The push rods 34 can individually be controlled by turning nuts 39. When the push rods 34 vertically move in an upper supporting body 30 and a lower supporting body 32, the respective blades 48 move. Lateral, namely, transverse flexibility is obtained by links 44 fitted to the blades 48. The flexibility is required since small lateral shift occurs in an interval between the push rods 34 when the plural blades 48 move so that they break a straight line. Then, stress or distortion owing to the shift of the blades is reduced by the slots in the blades 48.
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