POSITIVE TYPE PHOTOSENSITIVE-RESIN COMPOSITION AND PHOTO-SENSITIVE ELEMENT USING SAME

PURPOSE: To obtain a photosensitive resin compsn. having high sensitivity and resolution and giving a satisfactory resist shape by incorporating a specified single-dispersible vinyl polymer and a compd. which generates an acid when irradiated with active light. CONSTITUTION: A single-dispersible vinyl polymer having a tert-amyloxy- carbonyl structure in each molecule and having a mol.wt. dispersity (D) [wt. average mol.wt. (Mw)/number average mol.wt. (Mn)] of 1.01-1.5 and a compd. which generates an acid when irradiated with active light are incorporated. The wt. average mol.wt. and the number average mol.wt. can easily be measured by a light scattering method and a membrane osmotic pressure method, respectively. The single-dispersible vinyl polymer is obtd. by bringing various vinyl monomers into anionic living polymn. The vinyl monomers include alkyl acrylate or alkyl methacrylate, acrylic acid or methacrylic acid and other vinyl monomer copolymerizable with them.