As the alky I group of 1 to 5 carbon atoms represented by R,  a linear or branched alkyl group is preferable, and specific 45  examples include a methyl group, an ethyl group, a propyl  group, an isopropyl group, an n-butyl group, an isobutyl  group, a tert-butyl group, a pentyl group, an isopentyl group  and a neopentyl group.  The "organic compound having a molecular weight of 500  or more" which can be used as a base component is broadly  classified into non-polymers and polymers.  In general, as a non-polymer, any of those which have a  molecular weight in the range of 500 to less than 4,000 is used  Hereafter, a non-polymer having a molecular weight in the  range of 500 to less than 4,000 is referred to as a low molecu› lar weight compound.  As a polymer, any of those which have a molecular weight  of 1,000 or more is generally used. Hereafter, a polymer  having a molecular weight of 1,000 or more is referred to as  a polymeric compound. With respect to a polymeric com› pound, the "molecular weight" is the weight average molecu- lar weight in terms of the polystyrene equivalent value deter- mined by gel permeation chromatography (GPC). Hereafter,  a polymeric compound is frequently referred to simply as a  "resin".  <Component (A’)>  [Component (Al’)]  The polymeric compound (Al’) (hereafter, referred to as  "component (Al’)") includes a structural unit (a5-l) repre› sented by the aforementioned general formula ( a5- l ), a struc› tural unit (a0-1) represented by the aforementioned general  formula (a0-1) and a structural unit (a0-2) that generates acid  upon exposure.  The component (Al’) may include a structural unit (al)  derived from an acrylate ester containing an acid dissociable,  dissolution inhibiting group, as well as the aforementioned  structural units (a5-l), (a0-1) and (a0-2).  The component (Al’) may further include a structural unit  (a2) derived from an acrylate ester containing a lactone-con› taining cyclic group.  The component (Al’) may further include a structural unit  (a3) derived from an acrylate ester containing a polar group› containing aliphatic hydrocarbon group.  (Structural Unit (a5-l))  The structural unit ( a5- l) is a structural unit represented by  the aforementioned general formula (a5-l).  In general formula (a5-l), R represents a hydrogen atom,  an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl  group of 1 to 5 carbon atoms.  The halogenated alkyl group of 1 to 5 carbon atoms repre- sented by R is a group in which part or all of the hydrogen  atoms of the aforementioned alkyl group of 1 to 5 carbon  atoms have been substituted with halogen atoms. Examples  of the halogen atom include a fluorine atom, a chlorine atom,  a bromine atom and an iodine atom, and a fluorine atom is  particularly desirable.  As R, a hydrogen atom, an alkyl group of 1 to 5 carbon  atoms or a fluorinated alkyl group of 1 to 5 carbon atoms is  preferable, and a hydrogen atom or a methyl group is particu- larly desirable in terms of industrial availability.  In general formula (a5-l), a represents an integer of0 to 4,  preferably 0 or 1, and most preferably 0 from an industrial  viewpoint.  Further, a in general formula (a5-l) may be the same or  different from a in general formula ( a0-1) described later or a  in general formula (a0-2’) described later.  Specific examples of the aliphatic hydrocarbon group  include a linear or branched aliphatic hydrocarbon group, an  The aliphatic hydrocarbon group may be saturated or  unsaturated. In general, the aliphatic hydrocarbon group is  preferably saturated.  The hydrocarbon group may be either an aliphatic hydro› carbon group or an aromatic hydrocarbon group. An "ali› phatic hydrocarbon group" refers to a hydrocarbon group that  has no aromaticity.  A hydrocarbon "has a substituent" means that part or all of  the hydrogen atoms within the hydrocarbon group is substi› tuted with groups or atoms other than hydrogen.  In general formula (a0-1), R 1  represents a hydrocarbon  group of at least 10 carbon atoms which may have a substitu› ent.  Further, R $^{7 }$may be the same or different from R $^{7 }$in general  formula (a0-2’) described later.  In general formula (a0-1), R $^{7 }$represents a hydrogen atom  or an alky I group ofl to 5 carbon atoms. Examples of the alky I  group of 1 to 5 carbon atoms represented by R 7  include the  same alkyl group of 1 to 5 carbon atoms as those described  above for Ritz general formula ( a5-l ), and a hydrogen atom or  a methyl group is preferable.  In general formula ( 4-1 ), a and Rs are respectively the same  as defined for a and Rs in general formula (a5-l), and may be  the same or different from a and Rs in the aforementioned  general formula (a5-l) or a and Rs in general formula (a0-2’)  described later.  In general formula ( a0-1 ), R is the same as defined for R in  general formula (a5-l).  The structural unit ( a0-1) is a structural unit represented by  the aforementioned general formula (a0-1).  (Structural Unit (a0-1))  By ensuring the above-mentioned range, an excellent con› trast can be obtained, and lithography properties are  improved.  In the component (Al’) the amount of the structural unit  (a5-l) based on the combined total of all structural units  constituting the component (Al’) is preferably 30 to 90 mo!  %, more preferably 50 to 90 mo! %, and still more preferably  60 to 85 mo!  %.  As the structural unit ( a5-l ), one type of structural unit may  be used alone, or two or more types of structural units may be  used in combination.  Further, Rs in general formula (a5-l) may be the same or  different from Rs in general formula ( a0-1) described later or  Rs in general formula (a0-2’) described later.  When a represents 2, a desired combination of substitution  positions can be used, and the plurality of Rs may be the same  or different from each other.  When a represents 1, the substitution position of Rs may be  any of a-position, m-position or p-position.  Examples of the halogenated alkyl group of 1 to 5 carbon  atoms represented by Rs include the same halogenated alkyl  group of 1 to 5 carbon atoms as those described above for R,  and a fluorinated alkyl group is particularly desirable.  Examples of the alkyl group of 1 to 5 carbon atoms repre› sented by Rs include the same alkyl group of 1 to 5 carbon  atoms as those described above for R.  Examples of the halogen atom for Rs include a fluorine  atom, a chlorine atom, a bromine atom and an iodine atom,  and a fluorine atom is preferable.  In general formula ( a5-l ), examples of the substituent rep› resented by Rs include a halogen atom, an alkyl group of 1 to  5 carbon atoms and a halogenated alkyl group ofl to 5 carbon  atoms.  8  US 8,298,748 B2  7 