A radiation-sensitive resin composition includes: a resin including a structural unit represented by formula (1); at least one onium salt each including an organic acid anion moiety and an onium cation moiety; and a solvent. At least part of the organic acid anion moiety in the at least one onium salt includes an iodine-substituted aromatic ring structure. R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Y.sup.1 is a divalent linking group, and X.sup.1 is an acid-dissociable group, and n is 0 or 1. When n is 0, X.sup.1 is represented by formula (s1) or (s2).

##STR00001##

A radiation-sensitive resin composition includes: a resin including a structural unit represented by formula (1); at least one onium salt each including an organic acid anion moiety and an onium cation moiety; and a solvent. At least part of the organic acid anion moiety in the at least one onium salt includes an iodine-substituted aromatic ring structure. R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Y.sup.1 is a divalent linking group, and X.sup.1 is an acid-dissociable group, and n is 0 or 1. When n is 0, X.sup.1 is represented by formula (s1) or (s2).

##STR00001##

The present invention provides a titanium ligand-modified black phosphorus and the preparation method and use thereof. The titanium ligand-modified black phosphorus is a complex of black phosphorus and a titanium ligand having a structure represented by formula (I): ##STR00001##
wherein in the formula (I), R.sub.1 comprises C.sub.1-C.sub.6 alkyl, or phenyl optionally further substituted with 0 to 5 groups each independently selected from halogen atom, C.sub.1-C.sub.6 alkyl, nitro, hydroxy, amino or C.sub.1-C.sub.3 alkoxy; the C.sub.1-C.sub.6 alkyl or C.sub.1-C.sub.3 alkoxy is optionally further substituted with 0 to 3 groups each independently selected from halogen atom, nitro, hydroxy, amino, methyl, ethyl or n-propyl. The titanium ligand-modified black phosphorus of the present invention is not likely oxidized without changing inherent properties of the black phosphorus, and the antioxidant capacity is greatly enhanced.

The present invention provides a titanium ligand-modified black phosphorus and the preparation method and use thereof. The titanium ligand-modified black phosphorus is a complex of black phosphorus and a titanium ligand having a structure represented by formula (I): ##STR00001##
wherein in the formula (I), R.sub.1 comprises C.sub.1-C.sub.6 alkyl, or phenyl optionally further substituted with 0 to 5 groups each independently selected from halogen atom, C.sub.1-C.sub.6 alkyl, nitro, hydroxy, amino or C.sub.1-C.sub.3 alkoxy; the C.sub.1-C.sub.6 alkyl or C.sub.1-C.sub.3 alkoxy is optionally further substituted with 0 to 3 groups each independently selected from halogen atom, nitro, hydroxy, amino, methyl, ethyl or n-propyl. The titanium ligand-modified black phosphorus of the present invention is not likely oxidized without changing inherent properties of the black phosphorus, and the antioxidant capacity is greatly enhanced.

The present invention provides a resist composition, including: (A) a sulfonium salt containing an anion and a cation, the cation including a partial structure shown by the following general formula (A1); and (B) a polymer compound containing a repeating unit shown by the following general formula (B1). The present invention provides a resist composition that causes few defects and is excellent in lithography performance, having regulated acid diffusion, in photolithography using a high energy beam as a light source, and a resist patterning process using this resist composition.

##STR00001##

The present invention provides a resist composition, including: (A) a sulfonium salt containing an anion and a cation, the cation including a partial structure shown by the following general formula (A1); and (B) a polymer compound containing a repeating unit shown by the following general formula (B1). The present invention provides a resist composition that causes few defects and is excellent in lithography performance, having regulated acid diffusion, in photolithography using a high energy beam as a light source, and a resist patterning process using this resist composition.

##STR00001##

A resist composition comprising a base polymer and a sulfonium or iodonium salt capable of generating fluorobenzenesulfonic acid bonded to iodized benzoic acid offers a high sensitivity and minimal LWR independent of whether it is of positive or negative tone.

A resist composition comprising a base polymer and a sulfonium or iodonium salt capable of generating sulfonic acid bonded to iodized benzene ring offers a high sensitivity and minimal LWR independent of whether it is of positive or negative tone.

A resist composition comprising a base polymer and a quencher in the form of an iodonium salt capable of generating fluorobenzoic acid bonded to iodized benzene offers a high sensitivity and minimal LWR independent of whether it is of positive or negative tone.

A process for preparing diaryl sulfones, such as 4,4-dichlorodiphenylsulfone is disclosed. The process comprises contacting an aryl compound with sulfur trioxide to provide a benzene sulfonic acid. The benzene sulfonic acid is coupled to additional aryl compound in the presence of a catalyst. During the coupling step, the additional aryl compound is continuously added while water is removed.