A method and apparatus for translating a hierarchical IC layout file into a format that can be used by a mask writer that accepts files having a limited hierarchy. Cover cells of the original IC layout file or a modified file are designated, and the hierarchical file is redefined to include only those...http://www.google.com/patents/US7716624?utm_source=gb-gplus-sharePatent US7716624 - Mask creation with hierarchy management using cover cells
