Reference image contour generation

1. A method for reference image contour generation, comprising:

generating, by a processor in response to instructions stored on a non-transitory computer readable medium, a scanned image contour pattern, wherein generating the scanned image contour pattern comprises:

generating a mask pattern based on design target information;

generating a reference image based on a simulation of photolithographic effects on the mask pattern;

generating a reference image contour pattern based on edge detection in the reference image; and

generating the scanned image contour pattern as a function of the reference image contour pattern and a scanned image of an integrated circuit by:

dividing the scanned image contour pattern and the reference image contour pattern into corresponding sectors; and

comparing the scanned image contour pattern to the reference image contour pattern within each sector.

2. The method of claim 1 , wherein the simulation of photolithographic effects is a function of an optical model based on characteristics of a lens used to fabricate the integrated circuit.

3. The method of claim 1 , wherein the simulation of photolithographic effects is a function of an optical model based on characteristics of a photomask used to fabricate the integrated circuit.

4. The method of claim 1 , further comprising:

generating a simulation of photoresist effects that are a function of a photoresist model based on characteristics of a photoresist layer used to fabricate the integrated circuit; and

generating the reference image based on a combination of the simulation of photolithographic effects and the simulation of photoresist effects.

5. The method of claim 1 , further comprising:

detecting a defect in the integrated circuit in an area where the scanned image contour pattern does not coincide with a corresponding area of the reference image contour pattern.

6. The method of claim 1 , wherein the comparing is performed on a per-line basis.

7. The method of claim 1 , wherein the comparing is performed on a per-object basis.

8. The method of claim 1 , further comprising:

performing measurements of integrated circuit features identified in the scanned image contour pattern.

9. The method of claim 1 , further comprising retrieving the scanned image from a memory.

10. A method for reference image contour generation, comprising:

generating, by a processor in response to instructions stored on a non-transitory computer readable medium, a scanned image contour pattern, wherein generating the scanned image contour pattern comprises:

generating a mask pattern based on design target information;

generating a reference image based on a simulation of photoresist effects on the mask pattern;

generating a reference image contour pattern based on edge detection in the reference image; and

generating the scanned image contour pattern as a function of the reference image contour pattern and a scanned image of an integrated circuit by:

dividing the scanned image contour pattern and the reference image contour pattern into corresponding sectors; and

comparing the scanned image contour pattern to the reference image contour pattern within each sector.

11. The method of claim 10 , wherein the simulation of photoresist effects are a function of a photoresist model based on characteristics of a photoresist layer used to fabricate the integrated circuit.

12. The method of claim 10 , further comprising:

detecting a defect in the integrated circuit in an area where the scanned image contour pattern does not coincide with a corresponding area of the reference image contour pattern.

13. The method of claim 10 , wherein the comparing is performed on a per-line basis.

14. The method of claim 10 , wherein the comparing is performed on a per-object basis.

15. The method of claim 10 , further comprising:

performing measurements of integrated circuit features identified in the scanned image contour pattern.

16. An apparatus, comprising: a memory; and

a processor configured to execute instructions stored in the memory to:

generate a mask pattern based on design target information;

generate a reference image based on a simulation of photolithographic effects on the mask pattern;

generate a reference image contour pattern based on edge detection in the reference image; and

generate a scanned image contour pattern as a function of the reference image contour pattern and a scanned image of an integrated circuit by:

dividing the scanned image contour pattern and the reference image contour pattern into corresponding sectors; and

comparing the scanned image contour pattern to the reference image contour pattern within each sector.

17. The apparatus of claim 16 , wherein the processor is further configured to execute instructions stored in the memory to:

generate a simulation of photoresist effects that are a function of a photoresist model based on characteristics of a photoresist layer used to fabricate the integrated circuit; and

generate the reference image based on a combination of the simulation of photolithographic effects and the simulation of photoresist effects.

18. The apparatus of claim 16 , wherein the processor is further configured to execute instructions stored in the memory to:

detect a defect in the integrated circuit in an area where the scanned image contour pattern does not coincide with a corresponding area of the reference image contour pattern.