Negative-tone radiation-sensitive composition, cured pattern forming method, and cured pattern

A negative-tone radiation-sensitive composition comprising (A) a polymer, (B) a photoacid generator, and (C) a solvent,

• the polymer (A) being obtained by hydrolysis and condensation of at least one hydrolyzable silane compound selected from (1) a hydrolyzable silane compound shown by the following formula (1), (2) a hydrolyzable silane compound shown by the following formula (2), and (3) a hydrolyzable silane compound shown by the following formula (3),
• RaSi(OR1)4-a (1)
• wherein R represents a fluorine atom, a linear or branched alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkylcarbonyloxy group, R1 represents a monovalent organic group, and a represents an integer from 1 to 3,
• Si(OR2)4 (2)
• wherein R2 represents a monovalent organic group,
• R3x(R4O)3-xSi—(R7)z—Si(OR5)3-yR6y (3)
• wherein R3 and R6 individually represent a fluorine atom, an alkylcarbonyloxy group, or a linear or branched alkyl group having 1 to 5 carbon atoms, R4 and R5 individually represent a monovalent organic group, x and y individually represent a number from 0 to 2, and R7 represents an oxygen atom, a phenylene group, or a group —(CH2)m— (wherein m represents an integer from 1 to 6), and z represents 0 or 1,
• the content of units derived from the compound (1) being 50 to 100 mol % of the total units forming the polymer (A).