Structural Effect of Polymer and Inhibitor on Alkali Dissolution and Dissolution Inhibition Characteristics
Journal of Photopolymer Science and Technology (Fotoporima Konwakai shi)
The relationship between the higher structure of resist polymers, such as novolak (NVK) and poly(hydroxystyrene) (PHS), and their alkali dissolution and dissolution inhibition characteristics were investigated. From the calculations of the polymers with molecular mechanics (MM) and molecular dynamics (MD), NVK exhibited the structure with intramolecular hydrogen bondings through ortho-ortho methylene bonds, while PHS formed them through the OH group on ortho position, thereby both giving
... d structures with OH groups in the molecular interior. The alkali dissolution of the polymers having such higher structures showed lower values, and these tendency corresponded to the interpretation of percolation mechanism with respect to the alkali dissolution of polymers. In order to estimate the higher structures of the polymers, the n values in the Henderson-Hasselbach equation were measured. The increase in the n values resulted in the decrease in the alkali dissolution of the polymers. Furthermore, the structural factors of dissolution inhibitors on chemical amplification resist were also studied for their inhibition characteristics. The acid decomposition of inhibitors were stepwise proceeded resulting in that the dissolution inhibitors significantly lost their inhibition ability at a certain step in decomposition. With selective use of this step, the dissolution discrimination of the resist could be improved.