Enhanced mask pattern-aware heuristics for optical proximity corrections for integrated circuits
This disclosure describes systems, methods, and devices related to optical proximity corrections to an integrated circuit photomask. A method may include identifying a first contour of a first adjacent polygon of a photomask predicted for a first polygon of an integrated circuit, the first contour excluding a first corner formed by a first edge and a second edge of the first polygon; identifying a second contour of a second adjacent polygon of a photomask predicted for a second polygon of the integrated circuit, the second contour excluding a second corner formed by a third edge and a fourth edge of the second polygon; generating a fast contour prediction based on corner rounding associated with the first contour and the second contour; and generating, based on the fast contour prediction, a minimum distance between the first contour and the second contour, the minimum distance associated with the optical proximity corrections.
1 . A method for optical proximity corrections to an integrated circuit photomask, the method comprising:
identifying, by processing circuitry of a device, a first contour of a first adjacent polygon of a photomask predicted for a first polygon of an integrated circuit and for a second polygon of the integrated circuit, the first contour excluding a first corner formed by a first edge and a second edge of the first polygon;
identifying, by the processing circuitry, a second contour of a second adjacent polygon of the photomask, the second contour excluding a second corner formed by a third edge and a fourth edge of the second polygon;
identifying geometric parameters comprising lengths of mask segments forming the first corner and the second corner;
generating, by the processing circuitry, a fast contour prediction using a pre-calibrated heuristic function that calculates approximate mask corner rounding based on the identified geometric parameters, wherein the pre-calibrated heuristic function is fitted to a mask process model associated with approximating a closest approach between mask contours; and
generating, by the processing circuitry, based on the fast contour prediction, a minimum distance between the first contour and the second contour, the minimum distance associated with the optical proximity corrections to the integrated circuit photomask.
2 . The method of claim 1 , further comprising:
determining a first distance between the first corner and the second corner;
determining a second distance between the first corner and the first contour; and
determining a third distance between the second corner and the second contour,
wherein the minimum distance is based on the first distance, the second distance, and the third distance.
3 . The method of claim 2 , wherein the minimum distance is based on a sum of the first distance, the second distance, and the third distance.
4 . The method of claim 3 , further comprising:
generating an angle with respect to a horizontal axis based on a line between the first corner and the second corner,
wherein the minimum distance is further based on the angle.
5 . The method of claim 4 , wherein the first distance and the second distance are based on the angle.
6 . The method of claim 5 , wherein the first distance is further based on a minimum value of the first edge and the second edge, and wherein the second distance is further based on a minimum value of the third edge and the fourth edge.
7 . The method of claim 1 , wherein the first contour is a first Bezier curve, and wherein the second contour is a second Bezier curve.
8 . The method of claim 7 , wherein the minimum distance is not based on the first corner or the second corner.
9 . A non-transitory computer-readable storage medium comprising instructions to cause processing circuitry of a device for optical proximity corrections to an integrated circuit photomask, upon execution of the instructions by the processing circuitry, to:
identify a first contour of a first adjacent polygon of a photomask predicted for a first polygon of an integrated circuit and for a second polygon of the integrated circuit, the first contour excluding a first corner formed by a first edge and a second edge of the first polygon;
identify a second contour of a second adjacent polygon of the photomask, the second contour excluding a second corner formed by a third edge and a fourth edge of the second polygon;
identify geometric parameters comprising lengths of mask segments forming the first corner and the second corner;
generate a fast contour prediction using a pre-calibrated heuristic function that calculates approximate mask corner rounding based on the identified geometric parameters, wherein the pre-calibrated heuristic function is fitted to a mask process model associated with approximating a closest approach between mask contours; and
generate, based on the fast contour prediction, a minimum distance between the first contour and the second contour, the minimum distance associated with the optical proximity corrections to the integrated circuit photomask.
10 . The non-transitory computer-readable medium of claim 9 , wherein execution of the instructions further causes the processing circuitry to:
determine a first distance between the first corner and the second corner;
determine a second distance between the first corner and the first contour; and
determine a third distance between the second corner and the second contour,
wherein the minimum distance is based on the first distance, the second distance, and the third distance.
11 . The non-transitory computer-readable medium of claim 10 , wherein the minimum distance is based on a sum of the first distance, the second distance, and the third distance.
12 . The non-transitory computer-readable medium of claim 11 , wherein execution of the instructions further causes the processing circuitry to:
generate an angle with respect to a horizontal axis based on a line between the first corner and the second corner,
wherein the minimum distance is further based on the angle.
13 . The non-transitory computer-readable medium of claim 9 , wherein the first contour is a first Bezier curve, and wherein the second contour is a second Bezier curve.
14 . The non-transitory computer-readable medium of claim 13 , wherein the minimum distance is not based on the first corner or the second corner.
15 . An apparatus of a device for optical proximity corrections to an integrated circuit photomask, the apparatus comprising memory coupled to processing circuitry, wherein the processing circuitry is configured to:
identify a first contour of a first adjacent polygon in a photomask predicted for a first polygon of an integrated circuit and for a second polygon of the integrated circuit, the first contour excluding a first corner formed by a first edge and a second edge of the first polygon;
identify a second contour of a second adjacent polygon in the photomask, the second contour excluding a second corner formed by a third edge and a fourth edge of the second polygon;
identify geometric parameters comprising lengths of mask segments forming the first corner and the second corner;
generate a fast contour prediction using a pre-calibrated heuristic function that calculates approximate mask corner rounding based on the identified geogmetric parameters, wherein the pre-calibrated heuristic function is fitted to a mask process model associated with approximating a closest approach between mask contours; and
generate, based on the fast contour prediction, a minimum distance between the first contour and the second contour, the minimum distance associated with the optical proximity corrections to the integrated circuit photomask.
16 . The apparatus of claim 15 , wherein the processing circuitry is further configured to:
determine a first distance between the first corner and the second corner;
determine a second distance between the first corner and the first contour; and
determine a third distance between the second corner and the second contour,
wherein the minimum distance is based on the first distance, the second distance, and the third distance.
17 . The apparatus of claim 16 , wherein the minimum distance is based on a sum of the first distance, the second distance, and the third distance.
18 . The apparatus of claim 17 , wherein the processing circuitry is further configured to:
generate an angle with respect to a horizontal axis based on a line between the first corner and the second corner,
wherein the minimum distance is further based on the angle.
19 . The apparatus of claim 15 , wherein the first contour is a first Bezier curve, and wherein the second contour is a second Bezier curve.
20 . The apparatus of claim 19 , wherein the minimum distance is not based on the first corner or the second corner.