Image quality of higher NA I-line projection lens

These days much attention is being paid to the potential of i-line lithography. We have manufactured a high numer ical aperture ( N. A. ) i-lme lens in order to study this potential. The lens specification is as follows magnification : 1/10 N. A. : 0. 65 field size : 5X5min. In this paper we first compare the difference between the image quality of g-line and i-line optics with the same resolution and then we present the results of our experiment with the new i-line lens which shows the considerable P055 ibil ity of sub-half micron 1 ithography with an i-l me optical stepper. 1.