Systems and methods for placement of dummy
metal fills while preventing disturbance of device matching and optionally limiting
capacitance increase are disclosed. A computer-
automated method for locating dummy fills in an
integrated circuit fabrication process generally comprises receiving an input
layout of the
integrated circuit and specification of device matching for the
integrated circuit and locating the dummy fills in the integrated circuit according to dummy rules while preserving device matching. Locating the dummy fills may include locating the dummy fills along the at least one
axis of symmetry where device matching is along an
axis of symmetry and locating the dummy fills so as to preserve matching of the repeated elements where device matching is repeated matched elements. The method may also include designating at least one net of the integrated circuit as a critical net, the critical nets being only a subset of all nets of the integrated circuit, identifying
metal conductors corresponding to each designated critical net from the
layout file, and delineating a net blocking
exclusion zone extending a distance of a minimum net blocking distance (NBD) from the
metal conductor for each metal conductor identified, wherein the step of locating locates the dummy fills outside of the net blocking
exclusion zone.