| 摘要 |
A double exposure method for enhancing the image resolution in a lithographic system, is presented herein. The invention comprises decomposing a desired pattern to be printed on the substrate into at least two constituent sub-patterns that are capable of being optically resolved by the lithographic system, coating the substrate with a first positive tone resist layer and a relatively thin second positive tone resist layer on top of a target layer which is to be patterned with the desired dense line pattern. The second resist material is absorbing exposure radiation during a first patterning exposure and, after development, during a second patterning exposure to prevent exposure of at least a portion of the first resist material, underneath exposed portions of the second resist material layer, to an exposure dose above a fraction of an energy-to-clear exposure dose associated with the first resist layer. |
