Patent ID: 8227183

Claim:
A pattern forming method, comprising: forming a resist film by applying, to a substrate, a resin composition containing a resin of which solubility in a positive developer which is an alkali developer increases and solubility in a negative developer consisting essentially of an organic solvent decreases under an action of an acid, the resin having a lactone group and a monocyclic or polycyclic alicyclic hydrocarbon structure, wherein the resin composition is capable of forming a resist film of which solubility in the positive developer increases and solubility in the negative developer decreases upon irradiation with actinic rays or radiation; exposing the resist film; and developing the resist film after the exposing with the negative developer consisting essentially of one or more organic solvents, wherein the lactone group is selected from the following groups: wherein n 2 represents an integer of 0 to 4; and Rb 2 represents a substituent, and when n 2 is an integer of 2 or more, a plurality of Rb 2 's may be the same or different, and the plurality of Rb 2 's may combine with each other to form a ring.