A radiation-sensitive composition includes a polymer including: an acid-labile side chain including an acid-labile group; and an iodo group-containing side chain including two or more iodo groups and one or more radiation-sensitive onium cation structure(s). A method of forming a resist pattern includes: applying the radiation-sensitive composition directly or indirectly on a substrate to form a resist film; exposing the resist film; and developing the resist film exposed. A polymer includes: an acid-labile side chain including an acid-labile group; and an iodo group-containing side chain including two or more iodo groups and one or more radiation-sensitive onium cation structure(s). A monomer is a vinyl compound including two or more iodo groups and one or more radiation-sensitive onium cation structure(s).

A radiation-sensitive composition includes a polymer including: an acid-labile side chain including an acid-labile group; and an iodo group-containing side chain including two or more iodo groups and one or more radiation-sensitive onium cation structure(s). A method of forming a resist pattern includes: applying the radiation-sensitive composition directly or indirectly on a substrate to form a resist film; exposing the resist film; and developing the resist film exposed. A polymer includes: an acid-labile side chain including an acid-labile group; and an iodo group-containing side chain including two or more iodo groups and one or more radiation-sensitive onium cation structure(s). A monomer is a vinyl compound including two or more iodo groups and one or more radiation-sensitive onium cation structure(s).

The present inventors found cyclic peptide compounds that interact with Ras, and non-natural amino acids useful for the production of the cyclic peptide compounds. The inventors also found that the cyclic peptide compounds inhibit the binding between Ras and SOS. In addition, the inventors found specific non-natural amino acids contained in the cyclic peptide compounds and methods for production thereof.

The present inventors found cyclic peptide compounds that interact with Ras, and non-natural amino acids useful for the production of the cyclic peptide compounds. The inventors also found that the cyclic peptide compounds inhibit the binding between Ras and SOS. In addition, the inventors found specific non-natural amino acids contained in the cyclic peptide compounds and methods for production thereof.

An onium salt monomer consists of a sulfonic acid anion containing a polymerizable group and being free of iodine and a triarylsulfonium cation containing iodine and fluorine. A resist composition comprising a polymer comprising repeat units derived from the monomer exhibits a high solvent solubility, high sensitivity and high contrast and forms a small-size pattern with satisfactory exposure latitude, edge roughness, dimension uniformity and depth of focus when processed by photolithography using high-energy radiation, as well as collapse resistance.

An onium salt monomer consists of a sulfonic acid anion containing a polymerizable group and being free of iodine and a triarylsulfonium cation containing iodine and fluorine. A resist composition comprising a polymer comprising repeat units derived from the monomer exhibits a high solvent solubility, high sensitivity and high contrast and forms a small-size pattern with satisfactory exposure latitude, edge roughness, dimension uniformity and depth of focus when processed by photolithography using high-energy radiation, as well as collapse resistance.

A radiation-sensitive composition contains a polymer having a partial structure represented by formula (1), and a radiation-sensitive acid generating substance. The radiation-sensitive composition satisfies one or more of requirement 1, requirement 2, and requirement 3. requirement 1: the partial structure represented by the formula (1) has two or more iodine atoms. requirement 2: the radiation-sensitive acid generating substance contains an onium salt having two or more iodine atoms. requirement 3: the partial structure represented by the formula (1) has an iodine atom, and the radiation-sensitive acid generating substance contains an onium salt having an iodine atom. In the formula (1), Y.sup.1 represents a divalent group represented by formula (2-1) or formula (2-2).

##STR00001##

A radiation-sensitive composition contains a polymer having a partial structure represented by formula (1), and a radiation-sensitive acid generating substance. The radiation-sensitive composition satisfies one or more of requirement 1, requirement 2, and requirement 3. requirement 1: the partial structure represented by the formula (1) has two or more iodine atoms. requirement 2: the radiation-sensitive acid generating substance contains an onium salt having two or more iodine atoms. requirement 3: the partial structure represented by the formula (1) has an iodine atom, and the radiation-sensitive acid generating substance contains an onium salt having an iodine atom. In the formula (1), Y.sup.1 represents a divalent group represented by formula (2-1) or formula (2-2).

##STR00001##

An onium salt containing a sulfonic acid anion having a substituted fused ring structure and an aromatic sulfonic acid structure is provided. A chemically amplified resist composition comprising the onium salt has satisfactory solvent solubility, high sensitivity, and high contrast, and forms a resist film with improved lithography properties such as EL and LWR.

An onium salt containing a sulfonic acid anion having a substituted fused ring structure and an aromatic sulfonic acid structure is provided. A chemically amplified resist composition comprising the onium salt has satisfactory solvent solubility, high sensitivity, and high contrast, and forms a resist film with improved lithography properties such as EL and LWR.