Characterization of 45 nm att-PSM lithography with a hyper-NA ArF tool

In the 45 nm half pitch node, a mask induced polarization effect is appeared. Also, this effect depends on optical diffraction orders. This is notable in an attenuated phase shift mask (att-PSM) rather than in a Cr binary mask (BIM). Diffraction efficiency is also different between dense patterns and larger pitch patterns. In lithography simulation, we have to use a rigorous method and to consider mask topology. With the rigorous method, focus tilt effect depending on mask pitch has been reported (Erdmann, 2005). Also, it has been reported that transmittance of att-PSM should be changed for 45 nm half pitch pattern (Sato et al., 2005). In this report, the authors investigate detailed characterization of the 45 nm att-PSM lithography with lithography simulation. In addition, we discuss impact of the focus tilt for ED-window and other characterization of the 45 nm att-PSM.