Abstract: A mask system for use by a lithographic system to project an image of a circuit design. The design includes at least one large feature and at least one nearby small feature. The mask comprises one or more shapes on a mask to project an image of the nearby small feature and, on the same mask or on a different mask, an opaque shape to project an image of the large feature. The opaque shape includes in a field thereof at least one dummy clear shape of size and configuration insufficient to be resolved. Light from the lithographic projection system may be projected through the opaque shape and the dummy clear shape to resolve an image of the large circuit feature on a resist layer of a wafer without resolving the clear shape on the resist layer, while simultaneously increasing optical flare on the resolved large circuit feature image.

Abstract: A method and system of determining a localized measure of regional pattern density in a fabrication process of a chip are disclosed. In one embodiment, the method includes determining pattern density values for each cell of a plurality of cells of interest; averaging the pattern density values for each cell within a first selected region about a target cell to determine the localized measure of regional pattern density for the target cell; storing the localized measure of regional pattern density for the target cell; and repeating the averaging and the storing for each of the plurality of cells. The simplification of data allows for a localized measure of regional pattern density determination in much less time than conventional techniques.

Abstract: A mask system for use by a lithographic system to project an image of a circuit design. The design includes at least one large feature and at least one nearby small feature. The mask comprises one or more shapes on a mask to project an image of the nearby small feature and, on the same mask or on a different mask, an opaque shape to project an image of the large feature. The opaque shape includes in a field thereof at least one dummy clear shape of size and configuration insufficient to be resolved. Light from the lithographic projection system may be projected through the opaque shape and the dummy clear shape to resolve an image of the large circuit feature on a resist layer of a wafer without resolving the clear shape on the resist layer, while simultaneously increasing optical flare on the resolved large circuit feature image.

Abstract: A method and system of determining a localized measure of regional pattern density in a fabrication process of a chip are disclosed. In one embodiment, the method includes determining pattern density values for each cell of a plurality of cells of interest; averaging the pattern density values for each cell within a first selected region about a target cell to determine the localized measure of regional pattern density for the target cell; storing the localized measure of regional pattern density for the target cell; and repeating the averaging and the storing for each of the plurality of cells. The simplification of data allows for a localized measure of regional pattern density determination in much less time than conventional techniques.