Ke. Gonsalves et al., Combinatorial approach for the synthesis of terpolymers and their novel application as very-high-contrast resists for x-ray nanolithography, J VAC SCI B, 18(1), 2000, pp. 325-327
Novel resist systems for x-ray lithography, specifically optimized in terms
of contrast enhancement are described. Based on terpolymers of methyl meth
acrylate (MMA)-tert-butylacrylate-polyhedral oligosilsesquioxanes (POSS) sy
nthesized by solution polymerization, these systems were optimized by a com
binatorial approach. It is shown that the mass ratio of MMA/POSS=85.7/14.3
leads to maximum contrast (23.5) without sacrificing the sensitivity (1350
mJ/cm(2)) which remains comparable to that of standard PMMA. Such major con
trast enhancement shows that the above organic/inorganic nanocomposites are
promising candidates for sub-100 nm lithography. (C) 2000 American Vacuum
Society. [S0734-211X(00)05101-5].