Method for forming resist pattern by irradiating a resist coating on a substrate, contacting the resist with organic solvent vapor and removing the irradiated portion

A method for forming a resist pattern consisting essentially of:

• (i) preparing a resist by coating on a substrate a photosensitive resin composition as a single layer, the composition consisting essentially of:
• (a) a polymer having one or more silyloxy groups,
• (b) a compound or polymer capable of generating an acid due to irradiation of an active light ray, and
• (c) optionally a binder resin;
• (ii) irradiating said resist with an active light ray through a pattern mask and letting said silyloxy groups dissociate from the polymer (a) to form silanol compounds;
• (iii) bringing the resist into contact with volatile organic solvent vapor formed from a solvent having a boiling point of not more than 150.degree. C. to remove said silanol compounds on an irradiated portion, resulting in making the irradiated portion removable by oxygen plasma, and
• (iv) subjecting said resist to oxygen plasma to remove the irradiated portion.