US 9,052,592 B2  110  109  Examples of the halogen atom as the substituent include a  fluorine atom, a chlorine atom, a bromine atom, and an iodine  atom, with a fluorine atom being preferable.  Examples of the halogenated alkyl group as the substituent  include a group in which some or all the hydrogen atoms of  the alkyl group are substituted with the halogen atom.  R$^{1 }$is preferably an optionally substituted aliphatic hydro› carbon group having 4 to 20 carbon atoms since lithography  properties such as sensitivity, EL margin, LWR and the like  are enhanced. Above all, each of groups represented by the  formulae (r-lc-1-1), (r-lc-1-2), (r-lc-2-1), (r-lc-2-7), (r-lc-6- 1), (r-lc-7-1), (r-sl-1-1), and (r-sl-1-18), respectively, an ali› phatic hydrocarbon group having the polar group as a sub› stituent,  or an optionally  substituted monocyclic  or  polycyclic alicyclic hydrocarbon group is more preferable in  terms of sensitivity and lithography properties.  In the formula (dl-1), Y 1 , R 2 , andR $^{3 }$are the same as Y1, R2 ,  and R $^{3 }$in the formula (a0-r-1).  In the formula ( dl-1 ), Y$^{1 }$is preferably an optionally sub- stituted linear or branched aliphatic hydrocarbon group, and  more preferably a linear or branched alkylene group having 1  to 5 carbon atoms.  In the formula (dl-1), each of R 2  and R 3  is preferably a  hydrogen atom. Both R 2  and R 3  are especially preferably a  hydrogen atom.  Hereinafter, specific preferred examples of the anion moi› ety of the component (Dl) are given below. In addition,  examples in which the structure of a part other than R $^{1 }$in the  following specific examples corresponds to the structures of $_{30 }$ the specific examples of the anion moiety of the partial struc› ture represented by the above-described general formula ( a0- r-1) are also shown.  [Chemical formula 51]  When the ratio (Dl)/(B) is the preferred lower limit value  or more, it is excellent in reducing roughness of the resist  pattern. In addition, the exposure margin (EL margin) is more  In the resist composition (1), the mixing ratio of the com› pound (D 1) to the acid generator component (B) is preferably  0.4 or more, more preferably 0.4 to 1.5, still more preferably  0.5 to 1.5, and especially preferably 0.6 to 1.2 in terms of a  molar ratio represented by (D 1 )/ (B) (hereinafter, also referred  to as "ratio (Dl )/(B)").  In the invention, the term "molar ratio represented by (D 1 )/  (B)" refers to a mixing ratio of the component (Dl) to the  component (B) contained in the resist composition, that is, a  proportion (molar ratio) of the content of the component (Dl)  to the content of the component (B).  When the content of the component (Dl) is the preferred  lower limit value or more, good lithography properties such,  in particular, as an improvement of roughness and a good  resist pattern shape are obtained. On the other hand, when it is  not more than the preferred upper limit value, the sensitivity  can be maintained at a satisfactory level, and the throughput is  also improved.  The content of the component (Dl) is preferably 0.5 part by  mass to 20 parts by mass, more preferably 1 part by mass to 15  parts by mass, and still more preferably 2 parts by mass to 12  parts by mass based on 100 parts by mass of the component  (A).  The component (D 1) may be used alone, or in combination  of two or more kinds thereof.  In the formula ( dl-1 ),  Mm+  represents an m-valent organic  cation and is the same as  Mm+  in the formula ( a0-r-1 ). Above  all, a cation moiety [ (Mm+)  $_{11}$ml is preferably an organic cation  represented by the general formula (ca-1), and more prefer› ably each of cations represented by the formulae ( ca-1-1) to  ( ca-1-67), respectively.  Cation Moiety of Component (Dl):  0  0  <I-<’  0  -p o~""  0  0  ~  0  ol::l}  o~""  0  -continued 