Defect control of immersion lithography with top coat material

193nm immersion lithography is the most promising lithography candidate toward 45nm node technology and beyond; because it is able to obtain larger DOF and higher resolution at a hyper NA lens design greater then 1.0. Also the recent progress of 193nm immersion lithography technology would be applicable to establish the high volume manufacturing process soon. However, immersion specific issue, such as the immersion specific defect (Gil et al., 2005) and the leaching of resists compound into immersion fluid (Tsuji et al., 2005), still exists without any effective countermeasure. In order to prevent these immersion specific criteria, topcoat is one of the most useful materials. In this report, we discuss the top coat development criteria that are the suppression ability for leaching material, the protection capability for water penetration, surface tension control and so on.