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group containing an ester bond or lactone ring, Y $^{2 }$is a single bond or ester bond, R$^{31 }$and R$^{32 }$are each independently an acid labile group, R$^{33 }$is fluorine, trifluoromethyl, cyano, a C$_{1 }$-C$_{6 }$ alkyl, C$_{1 }$-C$_{6 }$ alkoxy, C$_{2}$ -C$_{7 }$ acyl, C$_{2}$ -C$_{7 }$ acyloxy, or C$_{2}$ -C$_{7 }$ alkoxycarbonyl group, R$^{34 }$is a single bond or C$_{1 }$-C$_{6 }$ alkanediyl group in which some carbon may be replaced by an ether or ester bond, c is 1 or 2, d is an integer of O to 4, meeting lsc+ds5. 

8. The resist composition of claim 7, further comprising a dissolution inhibitor. 

9. The resist composition of claim 7 which is a chemically amplified positive resist composition. 

10. The resist composition of claim 1 wherein the iodized base polymer is free of an acid labile group. 

11. The resist composition of claim 10, further comprising a crosslinker. 

12. The resist composition of claim 10 which is a chemi› cally amplified negative resist composition. 

13. The resist composition of claim 1, further comprising an iodine-free quencher. 

14. The resist composition of claim 1, further comprising a surfactant. 

15. The resist composition of claim 1 wherein the iodized base polymer further comprises recurring units of at least one type selected from recurring units having the formulae (gl) to (g3): 

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wherein RA is each independently hydrogen or methyl, 12 

Z $^{1 }$is a single bond, phenylene, -O-Z -, ----C(=O)› Z11-Z12-, Z 11 is ---0- or -NH-, Z $^{12 }$is a C$_{1}$-C$_{6 }$ alkanediyl group, C$_{2}$ -C$_{6 }$ alkenediyl group or phenylene group, which may contain a carbonyl moiety, ester bond, ether bond or hydroxyl moiety, 2 

Z is a single bond, -Z $^{21}$-C(=0)---0-, -Z $^{21}$---0-, or -Z $^{21}$-0----C(=0)-, Z 21 is a C$_{1}$-C$_{12 }$ alkanediyl group which may contain a carbonyl moiety, ester bond or ether bond, 3 

Z is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, ---O-Z 32 -, or ----C(=0)› Z31-Z32-, Z 31 is -0- or -NH-, Z $^{32 }$is a C$_{1}$-C$_{6 }$ alkanediyl group, phenylene, fluorinated phenylene, trifluoromethyl-substituted phenylene group, or C$_{2}$-C$_{6 }$ alkenediyl group, which may contain a carbonyl moi› ety, ester bond, ether bond or hydroxyl moiety, 

R$^{41 }$to R$^{48 }$are each independently a C$_{1 }$-C$_{20 }$monovalent hydrocarbon group which may contain a heteroatom, any two ofR 43 , R $^{44 }$and R$^{45 }$or any two ofR46 , R $^{47 }$and R$^{48 }$may bond together to form a ring with the sulfur atom to which they are attached, 

A is hydrogen or trifluoromethyl, and Q- is a non-nucleophilic counter ion. 

16. A pattern forming process comprising the steps of applying the resist composition of claim 1 to form a resist film on a substrate, exposing the resist film to high-energy radiation, and developing the exposed resist film in a devel› oper. 

17. The process of claim 16 wherein the high-energy radiation is ArF excimer laser of wavelength 193 nm or KrF excimer laser of wavelength 248 nm. 

18. The process of claim 16 wherein the high-energy radiation is EB or EUV of wavelength 3 to 15 nm. 

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