Resist composition and patterning process

A salt compound having the formula (A′):

• wherein the ring R is a C2-C12 alicyclic group containing the nitrogen atom, the ring may contain an ether bond, thioether bond, carbonyl group, —N(R′)— or sulfonyl group, R′ is hydrogen, a C1-C6 saturated hydrocarbyl group or -L3-R3,
• L1, L2 and L3 are each independently a single bond, ester bond, sulfonyl group, or C1-C6 alkanediyl group, some hydrogen in the alkanediyl group may be substituted by a hydroxy moiety, optionally fluorinated C1-C12 hydrocarbyloxy moiety, or optionally fluorinated C2-C12 hydrocarbylcarbonyloxy moiety, and any methylene constituent in the alkanediyl group may be replaced by an ether bond, ester bond, amide bond, sulfonyl moiety, sulfonate bond, or sulfonamide bond, with the proviso that L1, L2 and L3 do not contain a tertiary ester structure,
• R1, R2 and R3 are each independently hydrogen, a C1-C16 saturated hydrocarbyl group, C6-C10 aryl group, C1-C16 saturated hydrocarbyl group substituted with at least three fluorine atoms, C6-C10 aryl group substituted with at least three fluorine atoms, or a combination thereof, one or both of R1 and R2 have at least three fluorine atoms,
• R4 is a single bond or carbonyl group,
• R5 is hydrogen, hydroxy group, optionally halogenated C1-C6 saturated hydrocarbyl group, optionally halogenated C1-C6 saturated hydrocarbyloxy group, optionally halogenated C2-C7 saturated hydrocarbylcarbonyloxy group, optionally halogenated C1-C4 saturated hydrocarbylsulfonyloxy group, fluorine, chlorine, bromine, amino group, nitro group, cyano group, —N(R51)—C(═O)—R52—, or —N(R51)—C(═O)—O—R52, R51 is hydrogen or a C1-C6 saturated hydrocarbyl group, R52 is a C1-C6 saturated hydrocarbyl group or C2-C8 unsaturated aliphatic hydrocarbyl group,
• s is an integer of 1 to 5, t is an integer of 0 to 3, and 1≤s+t≤5.