A Study of Acid Diffusion Behaviors of PAG by using Top Coat Method for EUVL

Semiconductor microfabrication technologies for the 22-nm generation require high-performance resists with superb exposure characteristics. Specifically, this means resolution, exposure sensitivity, and edge roughness values not exceeding 18 nm, 10 mJ/cm2, and 2 nm (3σ), respectively. Resist exposure characteristics must be evaluated using actual exposure spectra. Since six-mirror exposure optics now represents the mainstream, we installed a resist evaluation system[1] capable of obtaining reflectance spectra of these exposure optics at the BL3 beamline in the NewSUBARU synchrotron radiation facility and performed resist evaluations. The system allows evaluations of various parameters for lithography simulations, including exposure sensitivity, acid diffusion length, light desorption characteristics, Dill's ABC parameters, and quenching rate parameters. Using the top coat method, we examined the diffusion behavior of the acid generated by the PAG. This paper reports the results of our study.