7  US 9,323,150 B2  8  A$_{2 }$ represents a group that when acted on by an acid, is  cleaved.  [16] The composition according to any ofitems [1] to [15],  wherein the resin (Ab) has a weight average molecular weight  ranging from 1000 to 200,000.  [17] The composition according to item [16], wherein the  resin (Ab) has a weight average molecular weight ranging  from 1000 to 100,000.  [18] The composition according to item [17], wherein the  resin (Ab) has a weight average molecular weight ranging  from 1000 to 50,000.  [19] The composition according to item [18], wherein the  resin (Ab) has a weight average molecular weight ranging  from 1000 to 25,000.  [20] The composition according to any of items [1] to [19],  further comprising a basic compound.  [21] The composition according to item [20], wherein the  basic compound is a compound containing a functional group  with proton acceptor properties, which compound when  exposed to actinic rays or radiation, is decomposed to thereby  produce a compound exhibiting proton acceptor properties  lower than, or no proton acceptor properties due to dissipation  of, the proton acceptor properties of the compound, or exhib› iting acid properties derived from the proton acceptor prop› erties of the compound.  [22] The composition according to any ofitems [1] to [21],  further comprising a surfactant.  [23] The composition according to any ofitems [1] to [22],  further comprising a solvent.  [24] The composition according to item [23], wherein the  solvent comprises propylene glycol monomethyl ether  acetate.  [25] The composition according to item [24], wherein the  solvent comprises propylene glycol monomethyl ether.  [26] The composition according to any of items [1] to [25] 35  to be exposed to EUV light.  [27] The composition according to any of items [1] to [25]  to be exposed to a KrF excimer laser, electron beams or  X-rays.  [28] An actinic-ray- or radiation-sensitive film formed  from the composition according to any of items [1] to [27].  [29] A method of forming a pattern, comprising forming  the composition according to any of items [ 1] to [27] into a  film, exposing the film to light, and developing the exposed  film.  [30] The method according to item [29], wherein the expo› sure is performed using EUV.  [31] A semiconductor device manufactured by a process  comprising the method of item [29] or [30].  The present invention has made it feasible to provide an  actinic-ray- or radiation-sensitive resin composition that can  simultaneously satisfy high sensitivity, favorable roughness  performance, favorable pattern shape, favorable dry etching  resistance and reduction of development defects, and to pro› vide an actinic-ray- or radiation-sensitive film from the com- position and a method of forming a pattern.  Embodiments of the present invention will be described in  detail below.  Herein, the groups and atomic groups for which no state› ment is made as to substitution or nonsubstitution are to be  interpreted as including those containing no substituents and  also those containing substituents. For example, the "alkyl  groups" for which no statement is made as to substitution or  nonsubstitution are to be interpreted as including not only the  alkyl groups containing no substituents (unsubstituted alkyl  groups) but also the alkyl groups containing substituents  (substituted alkyl groups).  Further, the term "actinic rays" or "radiation" means, for  example, brightline spectra from a mercury lamp, far ultra› violet represented by an excimer laser, extreme ultraviolet  (EUV), X-rays and electron beams (EB). Herein, the term  "light" means actinic rays or radiation.  The term "exposure to light" unless otherwise specified  means not only irradiation with light, such as light from a  mercury lamp, far ultraviolet, X-rays or EUV light, but also  lithography using particle beams, such as electron beams and  ion beams.  The actinic-ray- or radiation-sensitive resin composition of  the present invention comprises, specified below, a resin (Aa)  containing repeating units (Aal) and (Aa2) and a resin (Ab)  that when acted on by an acid, changes its alkali solubility.  The resin (Aa) contains at least one repeating unit (Aal)  derived from monomers of general formula (aal-1) below  and at least one repeating unit (Aa2) derived from monomers  of general formula ( aa2-1) below. The incorporation of the  resin (Aa) in the composition of the present invention exerts  the effect of improving development defects. One reason  therefor would be that a fluorinated ester group existing at, for  example, an end of a side chain of the resin is hydrolyzed by  an alkali developer to thereby render the resin hydrophilic.  Further, the incorporation of the resin (Aa) in the composition  of the present invention exerts the effect of enhancing dry  etching resistance. One reason therefor would be the presence  of a benzene ring in the repeating unit (Aa2).  In general formula (aal-1),  Q$_{1 }$represents an organic group containing a polymerizable  group.  Each ofL$_{1 }$ and L$_{2 }$ independently represents a single bond  or a bivalent connecting group.  Rf represents an organic group containing a fluorine atom.  In general formula (aa2-1),  Rb represents a hydrogen atom, an optionally substituted  alkyl group, or a halogen atom.  S$_{1}$a, when two or more S$_{1}$as exist, each independently,  represents a substituent, and  pis an integer of0 to 5.  First, the repeating units (Aal) derived from monomers of  general formula (aal-1) will be described.  DETAILED DESCRIPTION OF THE INVENTION  [Resin (Aa)]  (aal-1)  (aa2-1) 