| 摘要 |
The present invention provides a lithographic difficulty metric that is a function of an energy ratio factor that includes a ratio of hard-to-print energy to easy-to-print energy of the diffraction orders along an angular coordinateθi of spatial frequency space, an energy entropy factor comprising energy entropy of said diffraction orders along said angular coordinateθi, a phase entropy factor comprising phase entropy of said diffraction orders along said angular coordinateθi, and a total energy entropy factor comprising total energy entropy of said diffraction orders. The hard-to-print energy includes energy of the diffraction orders at values of the normalized radial coordinates r of spatial frequency space in a neighborhood of r=0 and in a neighborhood of r=1, and the easy-to-print energy includes energy of the diffraction orders located at intermediate values of normalized radial coordinates r between the neighborhood of r=0 and the neighborhood of r=1. The value of the lithographic difficulty metric may be used to identify patterns in a design layout that are binding patterns in an optimization computation. The lithographic difficulty metric may be used to design integrated circuits that have good, relatively easy-to-print characteristics. |
