Disclosed herein are a top anti-reflective
coating polymer used in a
photolithography process, which is one of the fabrication processes for a
semiconductor device, a method for preparing the anti-reflective
coating polymer, and an anti-reflective
coating composition comprising the anti-reflective coating
polymer. Specifically, the top anti-reflective coating polymer is used in
immersion lithography for the fabrication of a sub-50 nm
semiconductor device. The top anti-reflective coating polymer is represented by Formula 1 below: wherein R1, R2 and R3 are independently
hydrogen or a
methyl group; and a, b and c represent the
mole fraction of each
monomer, and are in the range between about 0.05 and about 0.9. Since a top anti-reflective coating formed using the above anti-reflective coating polymer is not soluble in water, it can be applied to
immersion lithography using water as the medium for a
light source. In addition, since the top anti-reflective coating can reduce the reflectance from an underlayer, the uniformity of CD is improved, thus enabling the formation of an ultrafine pattern.