content_image/895834.jpg content_image/895835.jpg
said metal salt being present in an amount of 0.02 to 30 parts by weight per 100 parts by weight of the polymer. 

2. The chemically amplified resist composition of claim 1, wherein in addition to the recurring units (al) and (a2), the copolymer comprises recurring units (bl), (b2) or (b3) of a sulfonium salt having the general formula (2): 

<img src='content_image/895834.jpg'>

whereinR 120 , R 124 , andR 128 eacharehydrogenormethyl, R 121 is a single bond, phenylene, ---0-R-, or ----C( =0)-Y -R-, Y is oxygen or NH, Risa straight, branched or cyclic C 1 -C 6 alkylene group, C 3 -C$_{10 }$ alk- 30 enylene or phenylene group, which may contain a car› bonyl, ester, ether or hydroxyl moiety, R 122 , R 123 , R 125 , R 126 , R 127 , R 129 , R 130 , and R 131 are each independently a straight, branched or cyclic C 1 -C$_{12 }$alkyl group which may contain a carbonyl, ester or ether moiety, or a 35 CcC$_{12 }$ aryl, C 7 -C$_{20 }$ aralkyl, or thiophenyl group which may contain a straight, branched or cyclic C 1 -C$_{10 }$alkyl, halogen, trifluoromethyl, cyano, nitro, hydroxyl, alkoxy, alkoxycarbonyl or acyloxy radical, Z 1 is a single bond or ----C(=0)-Z 3 -R 132 -, Z 2 is a single bond, methyl- 40 ene, ethylene, phenylene, fluorinated phenylene ---O-R 132 -or----C(=0)-Z 3 -R 132 , Z 3 is oxygen or NH, R 132 is a straight, branched or cyclic C 1 -C 6 alkylene group, alkenylene, orphenylene group, which may con› tain a carbonyl, ester, ether or hydroxyl moiety, a pair of 45 R122 and R123, R12s and R126, R12s and R127, R126 and R127,R129 andR130,R129 andR131,orR130 andR131 may bond directly or via a methylene moiety or ether bond to form a ring with the sulfur atom, R 133 is hydrogen or trifluoromethyl, M- is a non-nucleophilic counter ion, bl, b2 and b3 are in the range ofOsblsO.5, Osb2sO.5, Osb3sO.5, and Osbl+b2+b3sO.5. 50 

3. The chemically amplified resist composition of claim 1, further comprising at least one component selected from the group consisting of an organic solvent, a dissolution inhibitor, an acid generator, a basic compound, and a surfactant. 

4. The chemically amplified resist composition of claim 1, wherein the metal salt is present in an amount ofO.55 to 20 parts by weight per 100 parts by weight of the polymer. 

5. The chemically amplified resist composition of claim 1, wherein said metal salt is selected from the group consisting of the following general formulae: 

<img src='content_image/895835.jpg'>

wherein R 11 is each independently hydrogen, or a straight, branched or cyclic C 1 -C$_{20 }$ alky 1, C 2 -C$_{20 }$ alkeny 1, C 2 -C$_{20 }$ alkynyl, or C 6 -C 20 aryl group which may have a hydroxyl, ether, ester, amino, amide, sulfonic acid ester, halogen, cyano, nitro, carbonate, carbamate, thiol, sul› fide, thioketone radical or hetero-aromatic ring; R 12 is a single bond, or a straight, branched or cyclic C 1 -C$_{20 }$ alkylene, alkenylene, alkynylene, or C 6 -C 20 arylene group which may have a hydroxyl, ether, ester, amino, amide, sulfonic acid ester, halogen, cyano, nitro, carbon› ate, carbamate, thiol, sulfide, thioketone radical or het› ero-aromatic ring; R 13 and R 14 each are an alkylene, arylene, alkenylene or alkynylene group as defined for R 12 , in which one or two hydrogen atoms are substituted by one or two carboxyl groups. 

6. A pattern forming process comprising the steps of coat› ing the chemically amplified resist composition of claim 1 onto a substrate, baking, exposing to high-energy radiation, and developing with a developer. 

7. The process of claim 6 wherein the high-energy radiation is EUV radiation having a wavelength of 3 to 15 nm. 

8. The process of claim 6 wherein the high-energy radiation is an electron beam at an accelerating voltage of 1 to 150 ke V. 

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