Patent ID: 8977991
Filing Date: 2015-03-10
Classification: G06F

Abstract:
1. A routing method comprising: (a) receiving an integrated circuit (IC) layout for double patterning a layer of the IC using first and second photomasks, the layout including a plurality of circuit patterns, at least one of which is an uncolored pattern; (b) receiving an identification of a selected one of the plurality of circuit patterns having first and second endpoints, to be replaced by a replacement pattern connecting the first endpoint to a third endpoint, without receiving an indication in step (a) or (b) of whether the uncolored pattern is to be included in the first photomask or the second photomask, the first endpoint being connected to a cell; (c) removing the selected pattern from the layout; (d) reserving at least one keep-out region adjacent to the at least one uncolored pattern; (e) generating data representing the replacement pattern, such that no part of the replacement pattern intersects any of the plurality of circuit patterns or the at least one keep-out region; (f) storing the data representing the replacement pattern in a non-transitory machine readable storage medium, to be combined with data representing ones of the plurality of circuit patterns to be formed on the same photomask as the replacement pattern, on a machine readable storage medium to be read to fabricate the same photomask, wherein the steps of removing the selected pattern and replacing the selected pattern with the replacement pattern changes a circuit to which the cell is connected.