| 摘要 |
PURPOSE:To minimize the influence of dust sticking to a mask, by using plural masks and reducing transmitted energy per mask, and exposing the same position of a substrate several times. CONSTITUTION:An image obtained by a photomask 1 is reduced by a lens system 2 and projected on the substrate 3 by one shot to complete an exposure pattern. N Sets of masks 1 having the same pattern are used to reduce the amount of exposure per mask to 1/N as great as the basic amount of exposure and the substrate 3 is exposed to a one-shot image; and the substrate 3 is moved in an x-axis and a y-axis direction to form exposure patterns 4a-4c over the entire surface of the substrate successively for entire-surface exposure. Further, a prepared photomask 1 is replaced and the same operation is repeated by N times for superposition exposure. In this case, plural lens systems may be used to perform plural exposure shots simultaneously or to superpose images of those lens systems optically. Thus, the influence of dust sticking to a mask is minimized as much as possible. |
