| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an improved compensation against lens heating effects. <P>SOLUTION: An aberration compensation device can be used in lithography equipment has two elements capable of relatively rotating around an optical axis. One surface of each element has an aspheric shape which can be represented by a high-order Zernike polynomial equation. When two surfaces are aligned in respect of rotation, the device has a flat plate optical effect. When there exists a slight relative rotational deviation in the two elements of the device, the device effect is a phase shift which can be represented by aspheric shape differentiation. To compensate aberration due to lens heating, the compensation device can be used in a projection system with a lighting mode and a pattern type causing intensive off-axis localized pupil filling. <P>COPYRIGHT: (C)2008,JPO&INPIT |
