| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem in lithography apparatus wherein when critical size is reduced to print a fine pattern, that is, when resolution is increased, the focus depth becomes shallow, and prints a three-dimensional format, such as with a contact hole. <P>SOLUTION: Focus depth is increased using polarization. A polarization modifier 20 is inserted between a patterning device (for example, mask) MA of lithography apparatus 10 and a projection system PL, with the polarization modifier having birefringence changing radially. When the polarization modifier is made of a material, showing circular double refraction such as crystal, the focus depth becomes approximately twice as large as the focus depth when there is nothing inserted. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
