A deep ultraviolet photoresist based on 1,1’(dodecamethylene)bis(3‐diazo‐2,4‐piperidinedione) and poly(3‐methyl‐4‐hydroxystyrene) can be esterified at room temperature if the ultraviolet exposure is performed in a dry environment. No water‐free bake treatment during or after the exposure is necessary to obtain a high degree of esterification, as in the case of conventional diazonaphthoquinone/novolak based photoresists. Patternwise esterification results in 0.45 and 0.35 μm lines and spaces in the wet developable image reversal and the dry developable submicron positive dry etch resist process, respectively, using a 248 nm contact exposure.