Method and apparatus for determining mask layouts for a multiple patterning process

A computer-readable storage-medium storing instructions that when executed by a computer cause the computer to perform a method for determining mask layouts, the method comprising:

• identifying a set of critical edges in a design intent, wherein the set of critical edges is desired to be printed using a trench-split based multiple patterning process which prints opposing edges of a shape using different masks if the distance between the opposing edges is less than the minimum line width that can be printed using a single stage of the trench-split based multiple patterning process;
• creating a first set of mask shapes in a first mask layout for printing a first subset of critical edges in the design intent;
• creating a second set of mask shapes in a second mask layout for printing a second subset of critical edges in the design intent;
• in response to determining that a first mask shape in the first set of mask shapes does not abut a second mask shape in the second set of mask shapes, increasing the first mask shape's size by a first increment;
• and
• in response to determining that the second mask shape does not abut the first mask shape, increasing the second mask shape's size by a second increment.

An apparatus for determining mask layouts, the apparatus comprising:

• an identifying mechanism configured to identify a set of critical edges in a design intent, wherein the set of critical edges is desired to be printed using a trench-split based multiple patterning process which prints opposing edges of a shape using different masks if the distance between the opposing edges is less than the minimum line width that can be printed using a single stage of the trench-split based multiple patterning process;
• a first creating mechanism configured to create a first set of mask shapes in a first mask layout for printing a first subset of critical edges in the design intent;
• a second creating mechanism configured to create a second set of mask shapes in a second mask layout for printing a second subset of critical edges in the design intent;
• and
• an increasing mechanism configured to:
• in response to determining that a first mask shape in the first set of mask shapes does not abut a second mask shape in the second set of mask shapes, increase the first mask shape's size by a first increment, and
• in response to determining that the second mask shape does not abut the first mask shape, increase the second mask shape's size by a second increment.