Vinyl Addition Polymerization
Vinyl addition polymerization of alicyclics
Our project of systematically replacing hydrogen with fluorine on alicyclic units to their decrease absorbance is an ongoing project (see etch resistance section).However, preliminary results are encouraging enough to indicate that alicyclic units might be useful in 157 nm photoresist designs. Promising alicyclic monomer units can be readily prepared from the fluorinated acrylates described in the previous section. Additional alicyclic monomers can be envisioned from other fluorinated acrylates and olefins such as the pentafluoroisopropenyl acetate(1) or 3-bromo-1,1-difluoro-propene(2) shown below. This provides a pool of potential monomers to produce promising photoresist polymer candidates via transition metal-catalyzed vinyl addition polymerization. Several monomers have been prepared and experiments to produce polymers are underway.
    1)Y. V. Zeifman, S. A. Postovoi, L. S. German, Russ. Chem. Bl. 1994, 43(1), 170. 2)H. Muramatsu, P. Tarrant, J. Org. Chem. 1964, 29, 1796.
2nd Annual Symposium on 157 nm Lithography: UT Poster on Vinyl Addition Polymerization