PURPOSE: To obtain a resist film having high radiation sensitivity, high resolution and dry etching resistance and suitable for forming a micropattern for a photomask, etc. by using a specified alkoxyalkyl methacrylate polymer as a positive type resist material.

CONSTITUTION: A polymer of a monomer represented by the formula [where R is 2W10C alkoxyalkyl such as CH2OCH3, CH2CH2OCH3, CH2CH2CH2OCH3 or CH (OCH3)CH3] is dissolved in methylcellosolve acetate or the like optionally together with an adequate amount of a methacrylate polymer or polybutene 1-sulfone, and the soln. is applied to a semiconductor substrate or a mask substrate, dried and crosslinked by heating to form a resist film. The film is patterned with electron beams, etc. and wet or dry developed to obtain a pattern with high accuracy, high sensitivity and etching resistance.