In the current optical lithography, the resolution is being pushed for 45 nm half-pitch, and the chemically amplified
resist will be used for wide variety of applications including immersion lithography. So far the chemical amplification
has brought high performance for lithography. In the future, for the ArF lithography beyond 45nm half-pith, it will be
important to control pattern size. On the other hand, chemically amplified resist which utilized acid catalyzed deprotecting
reaction is sensitive to physical and chemical factor. Thus, there are various factors in the each process
(Resist coating, Pre bake, Exposure, Post exposure bake, Development and Rinse) to cause the resist blur. For example,
it's acid diffusion on PEB. The influence of these factors for the resist blur is a significant issue for lithography beyond
45 nm half-pitch. Therefore the need to reduce these factors on the resist blur becomes higher in order to extend the ArF
lithography beyond 45 nm half-pith.
In this paper, acid diffusion coefficient (D) and resist blur with changing anion size of PAG, size of protecting group
in typical ArF resist was reported. The relationship between acid diffusion coefficient and resist blur was discussed on
the basis of their difference in structure and characteristics.