US 2020/0050105 Al  3  Feb. 13, 2020  [0031]  In a further aspect, the invention provides an amine  compound having the formula (A’).  [0032]  Herein R1, X, m and n are as defined above. The  ring R 3  is a C$_{4}$ -C$_{6 }$ heterocycle formed with the nitrogen  atom, which may contain an ether bond, thioether bond,  -N(R 4 )-,  carbonyl group or sulfonyl group, R 4  is hydro› gen, C$_{1 }$-C$_{6 }$ alkyl, C$_{2}$ -C$_{6 }$ alkenyl, C$_{2}$ -C$_{8 }$ acyl, C$_{7}$-C$_{20 }$aralkyl  or C$_{1 }$-C$_{16 }$alkoxycarbonyl group.  [0033]  The iodized aromatic ring-containing amine com› pound is fully absorptive to EUV due to the inclusion of  iodine, has a sensitizing effect, and is quite effective for  suppressing acid diffusion by virtue of the large atomic  weight of iodine. Since the compound is not photosensitive  and is not decomposed in the exposed region, it has a high  ability to control acid diffusion in the exposed region and is  also effective for preventing a pattern from any film thick› ness loss by alkaline developer. Thus a resist composition  having a high sensitivity, low LWR and improved CDU is  designed.  Advantageous Effects of Invention  DESCRIPTION OF EMBODIMENTS  Resist Composition  [0034]  As used herein, the singular forms "a," "an" and  "the" include plural referents unless the context clearly  dictates otherwise. The notation  (Cn-Cm)  means a group  containing from n to m carbon atoms per group. As used  herein, the term "iodized" compound means an iodine› substituted compound. In chemical formulae, Me stands for  methyl, and Ac for acetyl.  [0035]  The abbreviations and acronyms have the follow› ing meaning.  [0036]  EB: electron beam  [0037]  EUV: extreme ultraviolet  [0038]  Mw: weight average molecular weight  [0039]  Mn: number average molecular weight  [0040]  Mw/Mn: molecular weight distribution or <lisper- sity  [0041]  GPC: gel permeation chromatography  [0042]  PEB: post-exposure bake  [0043]  PAG: photoacid generator  [0044]  LWR: line width roughness  [0045]  CDU: critical dimension uniformity  [0046]  The resist composition of the invention is defined  as comprising a base polymer and a quencher in the form of  an iodized aromatic ring-containing amine compound.  [0047]  The iodized aromatic ring-containing amine com› pound is an amine compound having an iodine-substituted  aromatic ring bonded to the nitrogen atom via a C$_{1 }$-C$_{20 }$ Iodized Aromatic Ring-Containing Amine Compound  divalent hydrocarbon group which may contain at least one  moiety selected from ester bond and ether bond. Preferably  the amine compound has the formula (A).  [0048]  In formula (A), R 1  is hydroxyl, a 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$^{1}$A----C(=O)-O-R$^{1}$B. R$^{1}$A is hydrogen ora C$_{1}$-C$_{6 }$ alkyl group.RIB is a C$_{1 }$-C$_{6 }$ alkyl, C$_{2}$-C$_{8 }$ alkenyl, C$_{6}$-C$_{12 }$aryl  or C$_{7}$-C$_{13 }$ aralkyl group.  [0049]  The C$_{1 }$-C$_{6 }$ alkyl group may be straight, branched or  cyclic, and examples thereof include methyl, ethyl, n-propyl,  isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert› butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl, and cyclo› hexyl. Examples of the alkyl moiety in the C$_{1}$-C$_{6 }$ alkoxy and  C$_{2}$-C$_{6 }$ acyloxy groups are as exemplified above for the alkyl  group.  [0050]  The C$_{2}$ -C$_{8 }$ alkenyl group may be straight, branched  or cyclic, and examples thereof include vinyl, 1-propenyl,  2-propenyl, butenyl, hexenyl and cyclohexenyl.  [0051]  Suitable C$_{6}$-C$_{12 }$ aryl groups include phenyl, tolyl,  xylyl, 1-naphthyl and 2-naphthyl. Suitable C$_{7}$-C$_{13 }$ aralkyl  groups include benzyl and phenethyl.  [0052]  Among others, R  1  is preferably fluorine, chlorine,  bromine, hydroxyl, amino, C$_{1 }$-C$_{3 }$ alkyl, C$_{1 }$-C$_{3 }$ alkoxy, C$_{2}$-C$_{4 }$ acyloxy, -NR$^{1}$A----C(=O)-R$^{1}$B or -NR$^{1}$A----C(=O)› O-R  IB.  When n is 2 or more, a plurality of groups R $^{1 }$may  be the same or different.  [0053]  R 2  is hydrogen, nitro, or a C$_{1}$-C$_{20 }$ monovalent  hydrocarbon group. The C$_{1 }$-C$_{20 }$ monovalent hydrocarbon  group may be straight, branched or cyclic. Examples thereof  include C$_{1 }$-C$_{20 }$ straight or branched alkyl groups such as  methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec› butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-de› cyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hep› tadecyl,  octadecyl,  nonadecyl,  and  icosyl;  C$_{3}$ -C$_{20 }$ monovalent saturated cycloaliphatic hydrocarbon groups  such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropyl› methyl, 4-methylcyclohexyl, cyclohexylmethyl, norbomyl,  and adamantyl; C$_{2}$-C$_{20 }$ straight or branched alkenyl groups  such as vinyl, propenyl, butenyl and hexenyl; C$_{2}$-C$_{20 }$mon› ovalent unsaturated cycloaliphatic hydrocarbon groups such  as cyclohexenyl and norbomenyl; C$_{2}$-C$_{20 }$ alkynyl groups  such as ethynyl, propynyl, butynyl, 2-cyclohexylethynyl,  and 2-phenylethynyl;  CcC$_{20 }$ aryl groups such as phenyl,  methylphenyl, ethylphenyl, n-propylphenyl, isopropylphe› nyl, n-butylphenyl isobutylphenyl, sec-butylphenyl, tert› butylphenyl,  naphthyl,  methylnaphthyl,  ethylnaphthyl,  n-propylnaphthyl,  isopropylnaphthyl,  n-butylnaphthyl,  isobutylnaphthyl, sec-butylnaphthyl, and tert-butylnaphthyl;  and C$_{7}$ -C$_{20 }$ aralkyl groups such as benzyl and phenethyl.  The foregoing monovalent hydrocarbon groups may contain  at least one moiety selected from hydroxyl, carboxyl, thiol,  ether bond, ester bond, nitro, cyano, halogen and amino  moiety.  (A’)  (A) 