| 摘要 |
A double exposure process is performed using a halftone phase shift mask ( 11 ) including gate patterns ( 1 ), assist patterns ( 2 a) and ( 2 b) with different resoluble line widths, and an assist pattern ( 2 c) with a line width equal to or smaller than a resolution limit which are respectively inserted into portions in each of which a distance between the gate patterns ( 1 ) is large, and a Levenson phase shift mask ( 11 ) including shifter patterns ( 3 ) corresponding to the gate patterns ( 1 ) of the photomask 11. On this occasion, the assist patterns ( 2 a), ( 2 b), and ( 2 c) are erased and only the gate patterns ( 1 ) are transferred. Consequently, when patterns are transferred by the double exposure process, a common depth of focus of the patterns is improved and highly uniform line widths are realized, which makes it possible to manufacture a highly reliable semiconductor device. |
