Focus and exposure parameters may be controlled in a lithographic process for manufacturing microelectronics by creating a complementary tone pattern of shapes and spaces in a resist film on a substrate. Corresponding dimensions of the resist shape and space are measured and the adequacy of focus or...http://www.google.de/patents/US5965309?utm_source=gb-gplus-sharePatent US5965309 - Focus or exposure dose parameter control system using tone reversing patterns
