Lithography options for the 32nm half pitch node and their implications on resist and material technology

Abstract

There still remain three major technological lithography options for high volume manufacturing at the 32nm half pitch node: 193nm immersion lithography with high index materials, enabling NA>1.6; 193nm double patterning and EUV lithography. In this paper the pros and cons of these three options will be discussed. Particular interest will be paid to the consequences of the final choice on the resist technology. High index 193nm immersion lithography also requires high index resist materials, which are under development but still far removed from the target refractive index and absorbance specifications not to mention lithographical performance. For double patterning the pitch may be relaxed, but the resists still need to be able to print very narrow lines and/or trenches. Moreover, it would be preferred for the resists to support pattern or image freezing techniques in order to step away from the litho-etch-litho-etch approach and make double patterning more cost effective. For EUV the resist materials need to meet very aggressive sensitivity specifications. In itself this is possible, but it is difficult to simultaneously maintain performance in terms of resolution and line width roughness. A new parameter (KLUP ) for assessing resist performance in terms of these three performance criteria will be introduced.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.