| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical integrator for an illumination system of a microlithographic projection exposure apparatus which can be manufactured by smaller effort. <P>SOLUTION: An optical integrator for an illumination system of a microlithographic projection exposure apparatus (10) comprises: an optical axis; and an array of first microlenses (70X) which are arranged in a first plane, have first refractive power in an X-direction perpendicular to the optical axis (OA), and have widths smaller than 2 mm in the X-direction. The integrator is further provided with an array of second microlenses (72X) to which a similar description is applied. The first and the second mirolenses (70X, 72X) have refracting surfaces that are curved in forms of circular arcs in intersecting planes, and can thus be manufactured more easily. According to the present invention, the total refractive power is split between the first refractive power and the second refractive power in such an optimized way that, in spite of the simpler shape of the microlenses, the extreme approximation of irradiance distribution in a subsequent field plane is obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT |
