Resist composition, method of forming resist pattern, compound, and acid diffusion-controlling agent

A compound represented by General Formula (d0):

• wherein R01, R02, R03, and R04 each independently represents a hydrogen atom, a hydroxy group, a halogen atom, or an alkyl group having 1 to 5 carbon atoms, alternatively, R01 and R02, R02 and R03, or R03 and R04 are bonded to each other to form an aromatic ring, the aromatic ring may have a substituent, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, Y represents a group that forms an alicyclic group together with a carbon atom *C, the alicyclic group that is formed by Y may have a substituent, where at least one of carbon atoms that form the alicyclic group is substituted with an ether bond, a thioether bond, a carbonyl group, a sulfinyl group, or a sulfonyl group, and m represents an integer of 1 or more, where Mm+ represents an m-valent organic cation selected from the group consisting of a sulfonium cation and an iodonium cation.

An acid diffusion-controlling agent comprising a compound represented by General Formula (d0):

• wherein R01, R02, R03, and R04 each independently represent a hydrogen atom, a hydroxy group, a halogen atom, or an alkyl group having 1 to 5 carbon atoms, alternatively, R01 and R02, R02 and R03, or R03 and R04 are bonded to each other to form an aromatic ring, the aromatic ring may have a substituent, R05 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, Y represents a group that forms an alicyclic group together with a carbon atom *C, the alicyclic group that is formed by Y may have a substituent, where at least one of carbon atoms that form the alicyclic group is substituted with an ether bond, a thioether bond, a carbonyl group, a sulfinyl group, or a sulfonyl group, and m represents an integer of 1 or more, where Mm+ represents an m-valent organic cation.