Function-integrated alicyclic polymer for ArF chemically amplified resists

We have designed a function-integrated alicyclic polymer, poly(carboxy-tetracyclo[4.4.0.1(2,5).1(7,10)]dodecyl methacrylate) (poly(CTCDDMA)), which has both a dry-etching resistant unit (the tetracyclododecyl group) and a carboxyl substituent, inducing alkaline-solubility. This polymer exhibits good dry-etching resistance; the etching rate for chlorine plasma is 1.2 times that for the novolac resist because it contains 100 mol% of the alicyclic groups. It also exhibits good solubility in a TMAH solution and good adhesion to the silicon substrate because of the hydrophilic carboxyl group. The chemically amplified resist composed of the ethoxyethyl-protected copolymer poly(CTCDDMA(67)-ECTCDDMA(33)) with a photoacid generator resolved a 0.15-mu m L/S pattern at 21.8 mJ/cm(2) using an ArF exposure system (NA = 0.55).