We describe photolithographic properties of poly(N-dodecylmethacrylamide-co-t-butyl 4-vinylphenyl carbonate) [p(DDMA-tBVPC)], which has a structure being subject to main chain scission and deprotection of t-butoxycarbonyloxy group by deep UV irradiation. Positive-tone patterns of the p(DDMA-tBVPC) Langmuir-Blodgett (LB) film with 60 layers were obtained by deep UV light irradiation followed by development with alkaline aqueous solution. The resolution of the pattern was 0.75 mum, which is the resolution limit of the photomask employed. The etching resistance of p(DDMA-tBVPC) LB film deposited for the pattern of the gold film is also investigated. (C) 2003 Elsevier Science B.V. All rights reserved.