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and R 3 , and/or R 3 and R 4 may bond together to form a ring, or a pair of R 1 and R 2 , R 1 and R 4 , R 2 and R 3 , or R $^{3 }$and R 4 , taken together, may form a double bond, R 11 is a C$_{2}$ -C$_{12 }$straight, branched or cyclic alkylene group which may contain an ether and/or ester moiety, x- is an anion selected from the group consisting on-, Br $_{2}$1-, Br1$_{2}$ - and 1$_{3}$-. 

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

4. The resist composition of claim 1, further comprising an organic solvent. 

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

6. A pattern forming process comprising the steps of $_{15 }$ coating the resist composition of claim 1 onto a substrate, baking, exposing the resulting resist film to high-energy radiation, and developing the resist film with a developer. 

7. The process of claim 6 wherein the high-energy radia› tion is ArF excimer laser of wavelength 193 nm or KrF excimer laser of wavelength 248 nm. 

8. The process of claim 6 wherein the high-energy radia› tion is EB or EUV of wavelength 3 to 15 nm. 

9. A chemically amplified resist composition comprising 

a quencher containing a quaternary ammonium salt selected from the group consisting of a quaternary ammonium iodide, quaternary ammonium dibromoio› dide, quaternary ammonium bromodiiodide, and qua› ternary ammonium triiodide, 

an acid generator, and a base polymer, 

wherein the acid generator is capable of generating sul› fonic acid, imidic acid or methide acid, and the base polymer consists of 

recurring units having the formula (al) or recurring units having the formula (a2), and at least one selected from the group consisting of 

recurring units (b) having a phenolic hydroxyl group as an adhesive group, 

recurring units ( c) having another adhesive group selected from the group consisting of hydroxyl ( other than the foregoing phenolic hydroxyl), lactone ring, ether, ester, carbonyl and cyano groups, 

recurring units ( d) selected from the group of units consisting of indene, benzofuran, benzothiophene, ace› naphthylene, chromone, coumarin, norbornadiene, and derivatives thereof, 

recurring units ( e) derived from compounds selected from 50 the group consisting of styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methyleneindene, vinyl› pyridine, and vinylcarbazole, and 

recurring units of at least one selected from recurring units having the formulae (fl) to (f3): 

<img src='content_image/908672.jpg'>

wherein RA is each independently hydrogen or methyl, R 21 and R$^{22 }$are each independently an acid labile group, X$^{1 }$is a single bond, phenylene, naphthylene, or a C$_{1 }$-C$_{12 }$ linking group containing ester moiety or lactone ring, and X 2 is a single bond or ester group, 

wherein RA is each independently hydrogen or methyl, Z 1 is a single bond, phenylene, -O-Z 11 , ----C(=O)› Z 12 -Z 11 -, is a C $_{1 }$-C$_{6 }$ straight, branched or cyclic alkylene group which may contain a carbonyl, ester, ether or hydroxyl moiety, or Z 11 is a C$_{2}$ -C$_{6 }$ straight, branched or cyclic alkenylene group which may con› tain a carbonyl, ester, ether or hydroxyl moiety, or Z 11 is a phenylene group, Z$^{12 }$is -0- or -NH-, Rs1, Rs2, Rs3, Rs4, Rs6, Rs7, and Rss are each 

Rss, independently a C$_{1 }$-C$_{12 }$ straight, branched or cyclic alkyl group which may contain a carbonyl, ester or ether moiety, or R 51 R 52 , R 53 , R 54 R 55 , R 56 , R 57 , and R 58 are each independently a CcC$_{12 }$ aryl, C$_{7}$ -C$_{20 }$ aralkyl, or mercaptophenyl group, 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$_{12 }$ straight, branched or cyclic alkylene group which may contain a carbonyl, ester or ether moiety, 3 

Z is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, ---O-Z 31 -, or ----C(=O)- 

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-continued 

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