The present invention provides photoacid generators for use in chemically amplified resists and lithographic processes using the same.

The invention relates to new polymers that comprise units that contain one or more photoacid generator groups and photoresists that contain the polymers. Preferred polymers of the invention are suitable for use in photoresists imaged at short wavelengths such as sub-250 nm or sub-200 nm, particularly 248 nm and 193 nm.

A radiation-sensitive composition containing a resist compound having a high sensitivity, a high resolution, a high etching resistance, and a low outgas which forms a resist pattern with a good shape is described.

A resist composition contains (A) a resin having a monocyclic or polycyclic cycloaliphatic hydrocarbon structure, the resin increasing its solubility in an alkali developer by an action of acid, (B) a compound generating acid upon irradiation with one of an actinic ray and a radiation, (C) particular an alkali soluble compound, and (D) a solvent.

A resist composition contains (A) a resin having a monocyclic or polycyclic cycloaliphatic hydrocarbon structure, the resin increasing its solubility in an alkali developer by an action of acid, (B) a compound generating acid upon irradiation with one of an actinic ray and a radiation, (C) particular an alkali soluble compound, and (D) a solvent.

A method for producing a resist composition includes at least a step of filtering a solution obtained by dissolving (A) a resin having a monocyclic or polycyclic cycloaliphatic hydrocarbon structure, the resin increasing its solubility in an alkali developer by an action of acid, (B) a compound generating acid upon irradiation with one of an actinic ray and a radiation, and (C) an alkali soluble compound having an alkyl group of 5 or more carbon atoms into (D) a solvent, through a filter.