Sulfonate and a resist composition

A chemical amplification type positive resist composition comprising

• a sulfonate of the formula (I):
• wherein A+ represents a counter ion and wherein Q1, Q2, Q3, Q4 and Q5 each independently represent a hydrogen, an alkyl having 1 to 16 carbon atoms, an alkoxy having 1 to 16 carbon atoms, a halogen, an aryl having 6 to 12 carbon atoms in which at least one hydrogen may be substituted by an alkyl, a cycloalkyl, an alkoxy, a hydroxyl or a halogen, an arylalkyl having 7 to 12 carbon atoms in which at least one hydrogen on an aryl ring may be substituted by an alkyl, a cycloalkyl, an alkoxy, a hydroxyl or a halogen, a cyano, a mercapto, an alkylthio having 1 to 16 carbon atoms, a hydroxy, a nitro or a group of the formula (I′)
• —COOR (I′)
• wherein R represents an aryl having 6 to 12 carbon atoms, a group of the formula (II′) or a group of the formula (II″)
• wherein R1 and R2 each independently represents an alkyl having 1 to 12 carbon atoms, a cycloalkyl having 3 to 12 carbon atoms, an arylalkyl having 7 to 12 carbon atoms or an aryl having 6 to 12 carbon atoms, and at least one hydrogen on an aryl ring in the arylalkyl or in the aryl may be substituted by an alkyl, a cycloalkyl, an alkoxy, a hydroxyl or a halogen, or R1 and R2 bond to form a monocyclic or polycyclic hydrocarbon group together with adjacent —C(Ra)—, Ra represents an alkyl having 1 to 8 carbon atoms, and —CH2— in the alkyl except the one at the terminal position may be substituted by —CO—, —O— or —S—, and R3 and R4 each independently represents a hydrogen, an alkyl having 1 to 12 carbon atoms, a cycloalkyl having 3 to 12 carbon atoms, an aryl having 6 to 12 carbon atoms, an arylalkyl having 7 to 12 carbon atoms, at least one hydrogen on the aryl ring in the aryl or in the arylalkyl may be substituted by an alkyl, a cycloalkyl, an alkoxy, a hydroxyl or a halogen, or R3 and R4 bond to form an monocyclic or polycyclic hydrocarbon group together with adjacent —CH—, with the proviso that at least one of Q1, Q2, Q3, Q4 and Q5 is a 1-alkylcycloalkyloxycarbonyl group;
• and
• a resin which contains a structural unit having an acid labile group and which itself is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid.