US 2020/0133122 Al  Apr.  30, 2020  134  wherein  R’a,  R:11’1, R:11’ 2 ,  R’c1, R’c 2  and R’c3 are each inde› pendently fluorine or a C$_{1 }$-C$_{40 }$ monovalent hydrocarbon  group which may contain a heteroatom, or a pair ofR:11’$^{1 }$and  R:11’ 2 ,  or R’c1 and R’c$^{2 }$may bond together to form a ring with  the carbon atom to which they are attached and any inter› vening atoms,  R’d  is a monovalent hydrocarbon group which  may contain a heteroatom,  wherein R 201  and R 202  are each independently a C$_{1}$-C$_{30 }$ monovalent hydrocarbon group which may contain a het› eroatom, R$^{203 }$is a C$_{1 }$-C$_{30 }$divalent hydrocarbon group which  may contain a heteroatom, any two of R  201 , R  $^{202 }$and R 203  may bond together to form a ring with the sulfur atom to  which they are attached,  LA is a single bond, ether bond or  a C$_{1 }$-C$_{20 }$ divalent hydrocarbon group which may contain a  heteroatom,  xa,  X 6 ,  xc and  Xd  are each independently  hydrogen, fluorine or trifluoromethyl, at least one  ofXa,  X 6 ,  xc and  Xd  being fluorine or trifluoromethyl.  13.  The resist composition of claim  7,  further comprising  a compound having the formula (5) or (6):  wherein Rq 1  is hydrogen or a monovalent hydrocarbon  group which may contain a heteroatom, exclusive of the  group wherein hydrogen bonded to the carbon atom at  a-position relative to the sulfa group is substituted by  fluorine or fluoroalkyl,  Rq 2  is hydrogen or a monovalent  hydrocarbon group which may contain a heteroatom, and  Mq+ is an onium cation.  14.  The resist composition of claim  7,  further comprising  an amine compound.  15.  The resist composition of claim  7,  further comprising  a surfactant which is insoluble or substantially insoluble in  (5)  (6)  (4)  water and soluble in alkaline developer, and/or a surfactant  which is insoluble or substantially insoluble in water and  alkaline developer.  16.  A pattern forming process comprising the steps of  applying the resist composition of claim  7  onto a substrate  to form a resist film, exposing a selected region of the resist  film to KrF excimer laser, ArF excimer laser, EB or EUV,  and developing the exposed resist film in a developer.  17.  The pattern forming process of claim  16  wherein the  developing step uses an alkaline aqueous solution as the  developer, thereby forming a positive pattern in which an  exposed region of the resist film is dissolved away and an  unexposed region of the resist film is not dissolved.  18.  The pattern forming process of claim  16  wherein the  developing step uses an organic solvent as the developer,  thereby forming a negative pattern in which an unexposed  region of the resist film is dissolved away and an exposed  region of the resist film is not dissolved.  19.  The pattern forming process of claim  18  wherein the  organic solvent is at least one solvent selected from the  group consisting of 2-octanone, 2-nonanone, 2-heptanone,  3-heptanone,  4-heptanone,  2-hexanone,  3-hexanone,  diisobutyl ketone, methylcyclohexanone, acetophenone,  methylacetophenone, propyl acetate, butyl acetate, isobutyl  acetate, pentyl acetate, butenyl acetate, isopentyl acetate,  propyl formate, butyl formate, isobutyl formate, pentyl  formate, isopentyl formate, methyl valerate, methyl pen› tenoate, methyl crotonate, ethyl crotonate, methyl propi› onate, ethyl propionate, ethyl 3-ethoxypropionate, methyl  lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl  lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxy› isobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate,  ethyl benzoate, phenyl acetate, benzyl acetate, methyl phe› nylacetate, benzyl formate, phenylethyl formate, methyl  3-phenylpropionate, benzyl propionate, ethyl phenylacetate,  and 2-phenylethyl acetate.  20.  The process of claim  16  wherein the exposure step is  carried out by immersion lithography while a liquid having  a refractive index of at least 1.0 is held between the resist  film and a projection lens.  21.  The process of claim  20,  further comprising the step  of coating a protective film on the resist film prior to the  exposure step, wherein immersion lithography is carried out  while the liquid is held between the protective film and the  projection lens.  *  *  *  *  * 