US 2020/0050105 Al  2  Feb. 13, 2020  Herein R  1  is hydroxyl, C 1  -C 6  alkyl group, C 1  -C 6  alkoxy  group, C 2 -C 6  acyloxy group, fluorine, chlorine, bromine,  amino group, -NR 1 A----C(=O)-R 1$_{B,}$ or $_{-NR}$1A----C  (=O)-O-R 1$_{B,}$ $_{R}$1 A is hydrogen or a C 1 -C 6  alkyl group,  RIB  is a C 1  -C 6  alkyl, C 2 -C 8  alkenyl, CcC 12  aryl or C 7 -C$_{13 }$ aralkyl group; R 2  is hydrogen, nitro, or a C 1 -C$_{20 }$monovalent  hydrocarbon group which may contain at least one moiety  selected from hydroxyl, carboxyl, thiol, ether bond, ester  bond, nitro, cyano, halogen and amino moiety, in case of  p=l, R 2  may bond together to form a ring with the nitrogen  atom to which they are attached, the ring optionally con› taining a double bond, oxygen, sulfur or nitrogen, or R 2  and  X may bond together to form a ring with the nitrogen atom  to which they are attached, the ring optionally containing a  double bond, oxygen, sulfur or nitrogen;  X is a C 1  -C$_{20 }$ divalent hydrocarbon group which may contain at least  moiety selected from ester bond and ether bond; m and n are  independently an integer meeting lsms5, 0sns4 and Ism+  ns5, and pis 1, 2 or 3.  [0019]  The resist composition may further comprise an  acid generator capable of generating a sulfonic acid, imide  acid or methide acid.  [0020]  The resist composition may further comprise an  organic solvent.  [0021]  In a preferred embodiment, the base polymer com› prises recurring units having the formula (al) or recurring  units having the formula (a2).  Herein  RA  is each independently hydrogen or methyl, R 11  and R 12  each are an acid labile group, Y 1  is a single bond,  phenylene group, naphthylene group, or C 1  -C 12  linking  group containing at least one moiety selected from ester  bond and lactone ring, and Y 2  is a single bond or ester bond.  [0022]  Typically, the resist composition is a chemically  amplified positive resist composition.  [0023]  In another embodiment, the base polymer is free of  an acid labile group.  [0024]  Also typically, the resist composition is a chemi› cally amplified negative resist composition.  [0025]  In a preferred embodiment, the base polymer fur› ther comprises recurring units of at least one type selected  from recurring units having the formulae  (fl) to (f3).  [0026]  Herein  RA  is each independently hydrogen or  methyl.  Z 1  is  a  single bond,  phenylene group,  or  ----C(=O)-NH-Z 11 -, Z 11  is a Cl-C6 alkanediyl group,  C 2 -C 6  alkenediyl group, or phenylene group, which may  contain a carbonyl, ester bond, ether bond or hydroxyl  moiety. Z 2  is a single bond, -Z 21 -C(=O)-O-,  -Z 21 - O- or -Z 21 ---0-C(=O)-, Z 21  is a cl -C12 alkanediyl  group which may contain a carbonyl moiety, ester bond or  ether bond. Z 3  is a single bond, methylene, ethylene, phe› nylene, fluorinated phenylene, ---O-Z 31 -, ----C(=O)› O-Z31-, or ----C(=O)-NH-Z 31 -, Z 31  is a C 1 -C 6  alkanediyl group, C 2 -C 6  alkenediyl group, phenylene group,  fluorinated phenylene group, or trifluoromethyl-substituted  phenylene group, which may contain a carbonyl moiety,  ester bond, ether bond or hydroxy moiety. R 21  to R 28  are  each independently a C 1  -C$_{20 }$ monovalent hydrocarbon  group which may contain a heteroatom, any two ofR 23 , R 24  and R 25  or any two of R 26 , R 27  and R 28  may bond together  to form a ring with the sulfur atom to which they are  attached, A is hydrogen or trifluoromethyl, and  M- is a  non-nucleophilic counter ion.  [0027]  The resist composition may further comprise a  surfactant.  [0028]  The resist composition may further comprise a  quencher other than the amine compound.  [0029]  In another aspect, the invention provides a process  for forming a pattern comprising the steps of applying the  resist composition defined herein onto a substrate, baking to  form a resist film, exposing the resist film to high-energy  radiation, and developing the exposed resist film in a devel› oper.  [0030]  Typically, the high-energy radiation is  ArF  excimer  laser radiation of wavelength 193 nm, KrF excimer laser  radiation of wavelength 248 nm,  EB, or EUV of wavelength  3 to 15 nm.  (al)  (a2)  +- y2  6  OR12  (fl)  (f2)  (fJ)  R26  I  +s-R 27  I  R2s 