Optimization of integrated circuits for a reticle transmission process window using multiple fill cells

摘要

Embodiments of the present invention include systems and methods of controlling reticle transmission. A process window for reticle transmission is received. For a given design, default fill cells of a default fill pattern are inserted in unused areas of an integrated circuit (IC). A pattern density is computed for each tile of an IC at each appropriate level, such as metallization levels and contact levels. An IC reticle transmission (RT) is computed for an area corresponding to an entire (or area of) IC or reticle. If the integrated circuit RT is outside of the process window, then the tiles that have an individual tile RT that is outside of the process window are identified and ranked into groups. Default fill cells in one group of tiles are replaced with replacement fill cells having an appropriate pattern and pattern density, and an updated IC RT parameter is computed until the updated IC RT parameter is within the process window.

主权项

1. A method for optimizing an integrated circuit for a reticle transmission (RT) process window, comprising:
receiving a lower RT limit and an upper RT limit defining the RT process window; applying default fill cells having a default cell pattern to a plurality of unused areas of the integrated circuit; generating a density table for a plurality of tiles, wherein each tile corresponds to a region of the integrated circuit, and the density table contains a tile RT parameter for said each tile; computing an initial integrated circuit RT parameter; determining whether the initial integrated circuit RT parameter is within the RT process window; identifying, in response to a condition wherein the initial integrated circuit RT parameter is outside of the RT process window, each tile of the plurality of tiles that has a tile RT parameter that is outside of the RT process window as an out-of-range tile; separating the out-of-range tiles into a plurality of groups, wherein each group corresponds to a tile RT parameter range; and replacing the default fill cells in at least one group of tiles with replacement fill cells having an appropriate pattern and pattern density.