Patent Number: 
Section: claims

1. A method for employing patterning process statistics for ground rules waivers and optimization, comprising:applying Optical Proximity Correction (OPC) to alter a ground rules layout using plan of record process methods to improve mask pattern images;simulating images produced by a mask;mapping patterning process variation distributions into an intersect area distribution by creating a histogram based upon a plurality of processes for the intersect area wherein mapping includes accumulating intersect area data for random process points and sorting the intersect area data into different bins, wherein given g and h as probability distribution functions, a ratio of a Monte Carlo sample count over a total sample size is given by g(x)h(y)dxdy, and if an intersect area function is a(x,y), then a distribution function f(z) for the intersect area is: f(z)dz=∫g(x)h(y)dxdy, for z≦a(x,y)≦z+d where, g, h and f are normalized probability distribution functions such that ∫g(x)dx=1 for all x, and ∫h(y)dy=1 for all y, and ∫f(z)dz=1 for all z; andanalyzing the intersect area using the histogram to provide ground rule waivers and optimization. 2. The method as recited in claim 1, wherein simulating images produced by a mask includes simulating images on computer through process lithography models. 3. The method as recited in claim 1, wherein applying OPC to alter a mask pattern using plan of record process methods includes applying lithographic exposure focus and dose distributions. 4. The method as recited in claim 1, wherein mapping patterning process variation distributions into an intersect area distribution includes analyzing the histogram to grant acceptable ground rules waivers and acceptable geometrical changes for a given a set of ground rules. 5. The method as recited in claim 1, further comprising, modifying a ground rules layout based upon the analyzing step. 6. The method as recited in claim 5, further comprising, fabricating a semiconductor chip in accordance with modified ground rules. 7. A computer program product employing patterning process statistics for ground rules waivers and optimization, comprising a computer useable medium including a computer readable program, wherein the computer readable program when executed on a computer causes the computer to:applying Optical Proximity Correction (OPC) to alter a ground rules layout using plan of record process methods to improve mask pattern images;simulating images produced by a mask;mapping patterning process variation distributions into an intersect area distribution by creating a histogram based upon a plurality of processes for the intersect area wherein mapping includes accumulating intersect area data for random process points and sorting the intersect area data into different bins, wherein given g and h as probability distribution functions, a ratio of a Monte Carlo sample count over a total sample size is given by g(x)h(y)dxdy, and if an intersect area function is a(x,y), then a distribution function f(z) for the intersect area is: f(z)dz=∫g(x)h(y)dxdy, for z≦a(x,y)≦z+d where, g, h and f are normalized probability distribution functions such that ∫g(x)dx=1 for all x, and ∫h(y)dy=1 for all y, and ∫f(z)dz=1 for all z; andanalyzing the intersect area using the histogram to provide ground rule waivers and optimization. 8. The computer program product as recited in claim 7, wherein simulating images produced by a mask includes simulating images on computer through process lithography models. 9. The computer program product as recited in claim 7, wherein applying OPC includes applying lithographic exposure focus and dose distributions. 10. The computer program product as recited in claim 7, wherein mapping the patterning process variation distributions into an intersect area distribution by creating a histogram includes analyzing the histogram to grant acceptable ground rules waivers and acceptable geometrical changes for a given a set of ground rules. 11. The computer program product as recited in claim 7, wherein the program further causes the computer to modify a ground rules layout based upon the analyzing step. 12. The computer program product as recited in claim 11, wherein the program further causes the computer to fabricate a semiconductor chip in accordance with modified wound rules. 13. A system employing patterning process statistics for ground rules waivers and optimization, comprising:a processing device configured to apply Optical Proximity Correction (OPC) to alter a ground rules layout to create a mask pattern to which patterning process variation distributions are applied to create, waive and optimize ground rules for semiconductor chip layouts; andan analysis module configured to map the patterning process variation distributions into an intersect area distribution by creating a histogram based upon a plurality of processes for an intersect area and to analyze the intersect area using the histogram to provide ground rule waivers and layout optimization wherein the map includes accumulated intersect area data for random process points and sorts the intersect area data into different bins, wherein given g and h as probability distribution functions, a ratio of a Monte Carlo sample count over a total sample size is given by g(x)h(y)dxdy, and if an intersect area function is a(x,y), then a distribution function f(z) for the intersect area is: f(z)dz=∫g(x)h(y)dxdy, for z≦a(x,y)≦z+d where, g, h and f are normalized probability distribution functions such that ∫g(x)dx=1 for all x, and ∫h(y)dy=1 for all y, and ∫f(z)dz=1 for all z. 14. The system as recited in claim 13, wherein the analysis module includes a software program run on the processing device. 15. The system as recited in claim 13, wherein processing device includes through process lithography models to simulate images produced by a mask. 16. The system as recited in claim 13, wherein the patterning process variation distributions include lithographic exposure focus and dose distributions. 17. The system as recited in claim 13, wherein the analysis module determines ground rules waivers and acceptable geometrical changes for a given a set of ground rules based upon the histogram. 18. The system as recited in claim 13, wherein the analysis module outputs a modified layout according to waived and optimized ground rules. 19. The system as recited in claim 18, wherein the modified layout is employed to fabricate a semiconductor chip. 20. The system as recited in claim 18, wherein an intersect area includes an area of overlap between a pair of layers in a layout.