The invention provides a method and structure for optimizing placement of redundant
vias within an integrated circuit design. The invention first locates target vias
by determining which vias do not have a redundant via. Then, the invention draws
marker shapes on or adjacent to the target vias. The marker shapes are only drawn
in a horizontal or vertical direction from each of the target vias. The invention
simultaneously expands all of the marker shapes in the first direction to a predetermined
length or until the marker shapes reach the limits of a ground rule. During the
expanding, different marker shapes will be expanded to different lengths. The invention
determines which of the marker shapes were expanded sufficiently to form a valid
redundant via to produce a first set of potential redundant vias and the invention
eliminates marker shapes that could not be expanded sufficiently to form a valid
redundant via.