content_image/913173.jpg content_image/913167.jpg content_image/913172.jpg content_image/913168.jpg content_image/913169.jpg content_image/913170.jpg
are not hydrogen at the same time, Rx and Ry may bond together to form a ring with the carbon atom to which they are attached, y is an integer of O to 2, u is O or 1, f is an integer satisfying Osfs5+2y-g, and g is an integer of 1 to 3. 

4. A negative resist composition comprising (A) a sulfo- nium compound having the formula (A) and (B) a base polymer containing a polymer comprising recurring units having the formula (B 1 ), 

wherein R1, R 2 , and R 3 are each independently a C$_{1}$-C$_{20 }$ straight, branched or cyclic monovalent hydrocarbon group which may contain a heteroatom, p and q are each indepen- dently an integer of O to 5, r is an integer of O to 4, in case of p=2 to 5, two adjoining groups R$^{1 }$may bond together to form a ring with the carbon atoms to which they are attached, in case of q=2 to 5, two adjoining groups R 2 may bond together to form a ring with the carbon atoms to which they are attached, in case of r=2 to 4, two adjoining groups R 3 may bond together to form a ring with the carbon atoms to which they are attached, 

wherein RA is hydrogen, fluorine, methyl or trifluorom› ethyl, R $^{11 }$is each independently halogen, an optionally 55 halogenated C$_{2}$-C$_{8 }$ straight, branched or cyclic acyloxy group, optionally halogenated C$_{1 }$-C$_{6 }$ straight, branched or cyclic alkyl group, or optionally halogenated C$_{1 }$-C$_{6 }$ straight, branched or cyclic alkoxy group, A $^{1 }$is a single bond or C$_{1 }$-C$_{10 }$ straight, branched or cyclic alkylene 60 group in which an ether bond may intervene in a carbon-carbon bond, s is O or 1, w is an integer of Oto 2, a is an integer satisfying Osas5+2w-b, and b is an integer of 1 to 3, 65 

wherein the polymer further comprises recurring units having the formula (B5): 

<img src='content_image/913173.jpg'>

<img src='content_image/913167.jpg'>

<img src='content_image/913172.jpg'>

wherein RA is as defined above, A 3 is a single bond or C$_{1 }$-C$_{10 }$ straight, branched or cyclic alkylene group in which an ether bond may intervene in a carbon-carbon bond, R $^{15 }$is each independently halogen, an optionally halogenated C$_{2}$ -C$_{8 }$ straight, branched or cyclic acyloxy group, optionally halogenated C$_{1 }$-C$_{6 }$ straight, branched or cyclic alkyl group, or optionally halogenated C$_{1 }$-C$_{6 }$ straight, branched or cyclic alkoxy group, W is hydro› gen, a C$_{1 }$-C$_{10 }$ straight, branched or cyclic monovalent aliphatic hydrocarbon group in which an ether, carbo› nyl or carbonyloxy moiety may intervene in a carbon› carbon bond, or an optionally substituted monovalent aromatic ring group, Rx and Ry are each independently hydrogen, an optionally hydroxy or alkoxy-substituted C$_{1 }$-C$_{15 }$ alkyl group or an optionally substituted mon› ovalent aromatic ring group, with the proviso that both Rx and Ry are not hydrogen at the same time, Rx and Ry may bond together to form a ring with the carbon atom to which they are attached, y is an integer of O to 2, u is O or 1, f is an integer satisfying Of 5+2y-g, and g is an integer of 1 to 3, 

wherein the polymer further comprises recurring units of at least one type selected from units having the formu› lae (al) to (a6): 

<img src='content_image/913168.jpg'>

<img src='content_image/913169.jpg'>

<img src='content_image/913170.jpg'>

