A resist composition comprising a sulfonium salt having an acid labile group of aromatic ring-containing tertiary ester type in the cation as the acid generator exhibits a high sensitivity and reduced LWR or improved CDU.

A positive resist composition comprising a base polymer comprising recurring units (a) having the structure of an ammonium salt of an iodized or brominated phenol, and recurring units (b1) having an acid labile group-substituted carboxyl group and/or recurring units (b2) having an acid labile group-substituted phenolic hydroxyl group exhibits a high sensitivity, high resolution, low edge roughness and dimensional uniformity, and forms a pattern of good profile after exposure and development.

A positive resist composition comprising a base polymer comprising recurring units (a) having the structure of an ammonium salt of an iodized or brominated phenol, and recurring units (b1) having an acid labile group-substituted carboxyl group and/or recurring units (b2) having an acid labile group-substituted phenolic hydroxyl group exhibits a high sensitivity, high resolution, low edge roughness and dimensional uniformity, and forms a pattern of good profile after exposure and development.

Method of forming pattern in photoresist layer includes forming photoresist layer over substrate, selectively exposing photoresist layer to actinic radiation forming latent pattern. Latent pattern is developed by applying developer to form pattern. Photoresist layer includes photoresist composition including polymer: ##STR00001##
A.sub.1, A.sub.2, L are direct bond, C4-C30 aromatic, C4-C30 alkyl, C4-C30 cycloalkyl, C4-C30 hydroxylalkyl, C4-C30 alkoxy, C4-C30 alkoxyl alkyl, C4-C30 acetyl, C4-C30 acetylalkyl, C4-C30 alkyl carboxyl, C4-C30 cycloalkyl carboxyl, C4-C30 hydrocarbon ring, C4-C30 heterocyclic, —COO—, A1 and A2 are not both direct bonds, and are unsubstituted or substituted with a halogen, carbonyl, or hydroxyl; A.sub.3 is C6-C14 aromatic, wherein A.sub.3 is unsubstituted or substituted with halogen, carbonyl, or hydroxyl; R.sub.1 is acid labile group; Ra, Rb are H or C1-C3 alkyl; R.sub.f is direct bond or C1-C5 fluorocarbon; PAG is photoacid generator; 0≤x/(x+y+z)≤1, 0≤y/(x+y+z)≤1, and 0≤z/(x+y+z)≤1.

A polymer comprising a first repeating unit including an amino group protected by an alkoxycarbonyl group; a second repeating unit including a nucleophilic group; and a third repeating unit including a crosslinkable group, wherein the first repeating unit, the second repeating unit, and the third repeating unit are different from each other.

A resist composition is provided comprising a base polymer and a quencher comprising a salt compound consisting of a cyclic ammonium cation and a 1,1,1,3,3,3-hexafluoro-2-propoxide anion having a trifluoromethyl, hydrocarbylcarbonyl or hydrocarbyloxycarbonyl group bonded thereto. The resist composition has a high sensitivity and forms a pattern with improved LWR or CDU, independent of whether it is of positive or negative tone.

Provided are a salt capable of producing a resist pattern with satisfactory CD uniformity (CDU), an acid generator, and a resist composition comprising the same. Disclosed are a salt represented by formula (I), an acid generator, and a resist composition comprising the same:

##STR00001##

wherein R.sup.4, R.sup.5, R.sup.7 and R.sup.8 each represent a halogen atom, a haloalkyl group or a hydrocarbon group; A.sup.1 and A.sup.2 each represent a hydrocarbon group, the hydrocarbon group may have a substituent, and —CH.sub.2— included in the hydrocarbon group may be replaced by —O—, —CO—, —S— or —SO.sub.2—; ml represents an integer of 1 to 5, m2, m4, m5 and m8 represent an integer of 0 to 5, m7 represents an integer of 0 to 4, 1≤m1+m7≤5, 0≤m2+m8≤5; and AI.sup.− represents an organic anion.

Provided are a salt capable of producing a resist pattern with satisfactory CD uniformity (CDU), an acid generator, and a resist composition comprising the same. Disclosed are a salt represented by formula (I), an acid generator, and a resist composition comprising the same:

##STR00001##

wherein R.sup.4, R.sup.5, R.sup.7 and R.sup.8 each represent a halogen atom, a haloalkyl group or a hydrocarbon group; A.sup.1 and A.sup.2 each represent a hydrocarbon group, the hydrocarbon group may have a substituent, and —CH.sub.2— included in the hydrocarbon group may be replaced by —O—, —CO—, —S— or —SO.sub.2—; ml represents an integer of 1 to 5, m2, m4, m5 and m8 represent an integer of 0 to 5, m7 represents an integer of 0 to 4, 1≤m1+m7≤5, 0≤m2+m8≤5; and AI.sup.− represents an organic anion.

A positive resist composition is provided comprising (A) a specific sulfonium salt as quencher, (B) a sulfonium salt consisting of a fluorinated sulfonate anion and a sulfonium cation as acid generator, and (C) a base polymer comprising repeat units having an acid labile group. The resist composition has a high sensitivity and resolution, improved LWR or CDU, and a broad process window and forms a pattern of good profile after exposure.

A radiation-sensitive resin composition includes: a polymer which has a first structural unit including a phenolic hydroxyl group, and a second structural unit represented by formula (1); and a radiation-sensitive acid generating agent which has a compound represented by formula (2). R.sup.1 represents a hydrogen atom, or the like; R.sup.2 represents a hydrogen atom or the like; and R.sup.3 represents a divalent monocyclic alicyclic hydrocarbon group having 3 to 12 ring atoms. Ar.sup.1 represents a group obtained by removing (q+1) hydrogen atoms on an aromatic ring from an arene formed by condensation of at least two benzene rings; R.sup.4 represents a monovalent organic group having 1 to 20 carbon atoms; q is an integer of 0 to 7; and R.sup.5 represents a halogen atom, a hydroxy group, a nitro group, or a monovalent organic group having 1 to 20 carbon atoms, or the like.

##STR00001##