US Patent 7382438 Lithographic apparatus and device manufacturing method

A lithographic apparatus having a controller that sets at least one lithographic apparatus parameter such that the difference between the critical dimension of pattern features formed on the substrate in regions of relatively high and relatively low pattern feature density is minimized for an area on the substrate on which a patterned beam of radiation is to be projected and which re-sets the at least one lithographic apparatus parameter during a time period between the times of projection of the patterned radiation beam onto two areas of the substrate.