US 2014/0030643 Al  3  Jan. 30,  2014  able roughness characteristic and reduction of residue defects  and to provide an actinic-ray- or radiation-sensitive resin film  therefrom and a method of forming a pattern using the com› position.  [0064]  The single FIGURE is a section view schematically  showing the definition of taper angle mentioned in Examples.  [0066]  Note that, with respect to the expression of a group  ( or an atomic group) used in this specification, the expression  without explicitly referring to whether the group is substi› tuted or unsubstituted encompasses not only groups with no  substituents but also groups having one or more substituents.  For example, the expression "alkyl group" encompasses not  only alkyl groups having no substituents (viz. unsubstituted  alkyl groups) but also alkyl groups having one or more sub› stituents (viz. substituted alkyl groups).  [0065]  The present invention will be described below.  nyl)imido group, a tris(alkylcarbonyl)methylene group, a tris  (alkylsulfonyl)methylene group or the like.  [0075]  As preferred alkali-soluble groups, there can be  mentioned a phenolic hydroxyl group, a carboxyl group, a  fluoroalcohol group (preferably hexafluoroisopropanol) and  a sulfonic acid group.  [0076]  The acid-decomposable group is preferably a group  as obtained by substituting the hydrogen atom of any of these  alkali-soluble groups with an acid-cleavable group.  [0077]  As the acid eliminable group, there can be men› tioned, for example, -C(R$_{36}$)(R$_{37}$)(R$_{38}$ ), -C(R 36 ) (R 37 )  (OR$_{39}$), ----C(R$_{01}$)(R$_{02}$)(OR$_{39}$) or the like.  [0078]  In the formulae, each of R$_{36 }$to R$_{39 }$independently  represents an alkyl group, a cycroalkyl group, a monovalent  aromatic ring group, a combination of an alkylene group and  a monovalent aromatic ring group or an alkenyl group. R$_{36 }$ and R$_{37 }$may be bonded with each other to thereby form a ring  structure.  [0079]  Each of R$_{01 }$ to R$_{02 }$ independently represents a  hydrogen atom, an alkyl group, a cycroalkyl group, a  monovalent aromatic ring group, a combination of an alky› lene group and a monovalent aromatic ring group or an alk› enyl group.  [0080]  Preferably, the acid-decomposable group is a cumyl  ester group, an enol ester group, an acetal ester group, a  tertiary alkyl ester group or the like. A tertiary alkyl ester  group is more preferred.  [0081]  The repeating unit (A) is preferably any of those of  general formula (V) below.  [0067]  In the present invention, the terms "actinic rays" and  "radiation" mean, for example, a mercury lamp bright line  spectrum, far ultraviolet rays represented by an excimer laser,  extreme ultraviolet rays, X-rays, electron beams and the like.  In the present invention, the term "light" means actinic rays or  radiation. The expression "exposure" used herein, unless oth› erwise noted, means not only light irradiation using a mercury  lamp, far ultraviolet, X-rays, EUV light, etc. but also lithog› raphy using particle beams, such as an electron beam and an  ion beam.  [0068]  The actinic-ray- or radiation-sensitive resin compo› sition of the present invention comprises [1] a resin that when  acted on by an acid, increases its solubility in an alkali devel› oper (hereinafter also referred to as an acid-decomposable  resin or resin (P)), [2] a compound that when exposed to  actinic rays or radiation, generates an acid (hereinafter also  referred to as an acid generator or compound (Q)), and [3] a  basic compound (R) with a structure to be specified below.  [0069]  The inventors have found that high sensitivity,  favorable pattern shape, favorable roughness characteristic  and reduction of residue defects can be attained by employing  a composition comprising a basic compound (R) with a speci› fied structure. Further, the inventors have found that this  effect is especially striking when a pattern is formed on an  acid substrate.  [0070]  The above-mentioned components of the composi› tion will be sequentially described below.  [0071]  [1] Acid-decomposable resin The composition of  the present invention contains an acid-decomposable resin  (P).  [0072]  <Repeating Unit (A)>  [0073]  The acid-decomposable resin comprises an acid› decomposable repeating unit (A). The repeating unit (A) is a  repeating unit that when acted on by an acid, is decomposed  to thereby generate an alkali-soluble group.  [0074]  As the alkali-soluble group, there can be mentioned  a phenolic hydroxyl group, a carboxyl group, a fluoroalcohol  group, a sulfonic acid group, a sulfonamido group, a sulfo› nylimido group, an (alkylsulfonyl)(alkylcarbonyl)methylene  group, an (alkylsulfonyl)(alkylcarbonyl)imido group, a bis  (alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imido  group, a bis(alkylsulfonyl)methylene group, a bis(alkylsulfo- [0082]  In general formula (V),  [0083]  each of Rs 1, Rs$_{2 }$ and Rs$_{3 }$ independently represents a  hydrogen atom, an alkyl group, a cycloalkyl group, a halogen  atom, a cyano group or an alkoxycarbonyl group, provided  that Rs$_{2 }$ may be bonded to Ls to thereby form a ring, which  Rs$_{2 }$ represents an alkylene group.  [0084]  Ls represents a single bond or a bivalent connecting  group, provided that when a ring is formed in cooperation  with Rs$_{2}$ ,  Ls represents a trivalent connecting group.  [0085]  Rs$_{4 }$ represents an alkyl group, and each ofRss and  Rs$_{6 }$ independently represents a hydrogen atom, an alkyl  group, a cycloalkyl group or a monovalent aromatic ring  group, provided that  Rss  and Rs $_{6 }$may be bonded to each other  to thereby form a ring, and provided that  Rss  and Rs$_{6 }$ are not  simultaneously hydrogen atoms.  [0086]  General formula (V) will be described in greater  detail below.  [0087]  As a preferred alkyl group represented by each of  Rs$_{1 }$ to Rs$_{3 }$ in general formula (V), there can be mentioned an  optionally substituted alkyl group having up to 20 carbon  atoms, such as a methy 1 group, an ethy 1 group, a propy 1 group,  an isopropyl group, an n-butyl group, a sec-butyl group, a  (V)  BRIEF DESCRIPTION OF DRAWINGS  DETAILED DESCRIPTION OF THE INVENTION 