PHOTORESIST RESIN AND PHOTORESIST RESIN COMPOSITION

摘要

A photoresist resin of the invention contains at least a constitutional repeating unit A containing a group capable of partially leaving by the action of an acid to thereby become soluble in an alkali, and a constitutional repeating unit B containing an alicyclic skeleton having a polar group, and has a weight-average molecular weight of 3000 to 15000 and has a content of polymer fractions each having a molecular weight exceeding 40000 of 4 percent by weight or less of the total resin. The molecular weight distribution (Mw/Mn) of the resin is, for example, from about 1.1 to about 3.0, and preferably from about 1.5 to about 2.5.