Method and apparatus for allowing phase conflicts in phase shifting mask and chromeless phase edges

摘要

Phase shifting layouts and masks with phase conflicts are described. The phase shifting layout defines light transmissive regions for use in defining selected features in a layer of material of an integrated circuit (IC). The phase shifting layout includes a phase conflict caused by two light transmissive regions that are out of phase with each other and which, without correction, would lead to the definition of an artifact in the layer of material. A corresponding mask adapted for use in conjunction with the phase shifting mask can ensure that the artifact is ultimately erased. The phase conflict is intentionally introduced into the phase shifting layout during phase assignment to permit all of the selected features to be defined using the phase shifting mask.