摘要 |
A mask 206 for use in an apparatus utilized for optically transferring a lithographic pattern corresponding to an integrated circuit from said mask 206 onto a semiconductor substrate, said apparatus utilizing off-cases illumination, said pattern including at least one feature, said mask 206 comprising: an additional feature 215, 216 adjacent to and surrounding said at least one feature, said additional feature 215, 216 being disposed at a predetermined distance from all edges of said at least one feature and having the same transparency as said at least one feature, the width of said additional feature 215, 216 being selected such that the depth of focus of said at least one feature is increased. <IMAGE> |