Development of Materials and Processes for Non-top Coat Immersion Lithography

Non-top coat resists are expected to be compatible with next generation high-speed scanners. Since they contain hydrophobic additives which are eccentrically located near the film surface so that they can form more hydrophobic film surface, they should have more suitable performance for high-speed scanning as well as better cost performance because of their processes without any immersion top coat steps. However, the influence of the addition of hydrophobic additives to the resists on their lithographic and defect performance need to be investigated, in order to apply them as mass production processes. In this work, the influence of hydrophobic additives on the scanning performance and on the imaging performance is investigated. Moreover, the influnece of global resist pattern density on a wafer on defect performance is also investigated. In addition, the defect performance is demonstrated to be sucessfully improved by improving the development and rinse processes.