A study on enhancing EUV resist sensitivity (2)

To improve EUV resist sensitivity, studies have sought to enhance EUV light absorption by adding metals characterized by high EUV light absorption to the resist polymer. This approach is intended to increase secondary electron emission, thereby enhancing PAG reactivity and improving acid generation efficiency [1-3]. As reported in our previous report, to determine whether adding metals characterized by high EUV light absorption actually enhances sensitivity, we performed transmittance measurements and sensitivity evaluations of resist samples doped with ZrO2 or TeO2 nanoparticles, which have low and high EUV light absorption, respectively, in molar quantities of 0-2 relative to PAG. The samples were subjected to EUV exposure at the NewSUBARU synchrotron radiation facility. The results of transmittance measurements and sensitivity evaluations showed that, while the ZrO2-doped resist showed no changes in absorption or sensitivity, the TeO2-doped resist showed enhancement in both properties. Based on these results, we confirmed that adding metals characterized by high EUV light absorption to the EUV resist enhances its EUV light absorption and increases secondary electron emission, thereby enhancing PAG reactivity and improving acid generation efficiency [4-5]. In the efforts discussed in the present report, we examined whether adding metals directly to PAG could further enhance sensitivity by increasing the EUV light absorption of PAG itself, thereby efficiently heightening the effect of the secondary electron emission on PAG. Key Word: EUV Lithography, Metal assignment PAG, Sn-,PAG, Te-PAG, EUV metal resist, Synchrotron International Conference on Extreme Ultraviolet Lithography 2017, edited by Paolo A. Gargini, Patrick P. Naulleau, Kurt G. Ronse, Toshiro Itani, Proc. of SPIE Vol. 10450, 104501E © 2017 SPIE · CCC code: 0277-786X/17/$18 · doi: 10.1117/12.2280377 Proc. of SPIE Vol. 1045