Patent ID: 8409786

Claim:
A manufacturing method of a semiconductor device, comprising: a first mask pattern being formed on a first photomask and a second mask pattern being formed on a second photomask respectively, wherein in at least one of the first photomask and the second photomask, a plurality of assist patterns which is not superimposed on the mask pattern of the other on an occasion of exposure and which is provided side by side as a striped pitch pattern in parallel with the first mask pattern or the second mask pattern is formed, and said method further comprising, a first exposing step of exposing the first mask pattern to a transfer object by using the first photomask; and a second exposing step of exposing the second mask pattern to the transfer object so that at least a part of the second mask pattern is superimposed on the first mask pattern, by using the second photomask; wherein in said second exposing step, the second mask pattern is exposed onto the transfer object by using a tri-tone mask in which a chrome mask and an attenuated phase shift mask are mixedly present, as the second photomask, and wherein at least one of the first exposing step and the second exposing step is performed by using double pole illumination.