Radiation-sensitive composition

1. A radiation-sensitive composition comprising:

a low-molecular-weight compound having one or more acid-dissociable groups which decompose by an action of an acid to enhance solubility in an alkaline developing solution and one or more radiation-sensitive acid-generating groups which generate an acid upon application of an active ray or radiation per molecule, and having a polystyrene-reduced number-average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 500 to 4,000, wherein the low-molecular-weight compound is not obtained from chain growth polymerization of a monomer with an unsaturated bond;

a solvent; and

a radiation-sensitive acid-generator other than the low-molecular-weight compound,

wherein a content of the low-molecular-weight compound is 80 mass % or more of 100 mass % of a total solid component of the radiation-sensitive composition, and

wherein the low-molecular-weight compound is a compound shown by a following formula (1),

wherein

A represents

an aliphatic group having 1 to 50 carbon atoms,

an aromatic group having 6 to 50 carbon atoms,

an organic group consisting of said aliphatic and said aromatic group, or

a group having a valence which is a sum of l+m+n and which has two or more of the aliphatic group represented by A, the aromatic group represented by A, or the organic group represented by A;

X represents —O—, —CH 2 C(═O)—O—, —C(═O)—O—, —OC(O)O—, or —Ar 1 —O—, wherein Ar 1 represents a 1,4-phenylene group;

R 1 represents an acid-dissociable group which is a substituted or unsubstituted tertiary hydrocarbon group having 4 to 12 carbon atoms or a substituted or unsubstituted acetal group;

Y represents —CH 2 —C(═O)—O—R 2 —, wherein R 2 represents a substituted or unsubstituted methylene group or a substituted or unsubstituted alkylene group having 2 to 30 carbon atoms;

l is an integer from 1 to 4;

m is an integer from 1 to 3;

n is an integer from 0 to 10; and

Z is an organic group shown by a formula (2), a formula (3), a formula (4), or a formula (5) and, in a case where m is 2 or 3, the organic groups represented by Z are either a same or different,

wherein

M 1 + in the formula (2) represents a monovalent onium cation;

M 2 + in the formula (3) represents a monovalent onium cation;

R 3 in the formula (3) and the formula (5) represents a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms or a substituted or unsubstituted aryl group having 1 to 15 carbon atoms;

P in the formula (4) represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms or a substituted or unsubstituted arylene group having 2 to 10 carbon atoms; and

Q in the formula (5) represents a group shown by a formula (6), a formula (7), or a formula (8),

wherein an amount of the radiation-sensitive acid generator is from 0.1 to 10 parts by mass for 100 parts by mass of the low-molecular-weight compound.

2. The radiation-sensitive composition according to claim 1 , further comprising an acid diffusion controller shown by

wherein

each R 16 is independently a hydrogen atom or a substituted or unsubstituted alkyl group, aryl group, or aralkyl group;

each of R 17 to R 21 is independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group; and

X − represents OH − , R 22 OH − , or R 22 COO − , wherein R 22 is a monovalent organic group.

3. The radiation-sensitive composition according to claim 2 , wherein an amount of the acid diffusion controller is from 0.1 to 1 part by mass for 100 parts by mass of an amount of the low-molecular-weight compound.

4. The radiation-sensitive composition according to claim 1 , wherein M 1 + in the formula (2) is a sulfonium cation, an iodonium cation, a phosphonium cation, a diazonium cation, an ammonium cation, or a pyridinium cation.

5. The radiation-sensitive composition according to claim 1 , wherein M 2 + in the formula (3) is a group shown by a formula (3-1), a formula (3-2), a formula (3-3), or a formula (3-4),

wherein

each R 4 independently represents an alkyl group, an alkoxyl group, a trifluoromethyl group, or a fluorine atom; and

k is independently an integer of 0 to 3.