94  US 8,962,233 B2  93  As the alkali-soluble resin for use in the present invention,  there can be mentioned, for example, a novolak resin, a  hydrogenated novolak resin, an acetone-pyrogallol resin, an  o-polyhydroxystyrene, a m-polyhydroxystyrene, a p-polyhy- droxystyrene, a hydrogenated polyhydroxystyrene, a haloge- nated or alkylated polyhydroxystyrene, a hydroxystyrene-N› substituted maleimide copolymer,  an o/p- and m/p› hydroxystyrene copolymer, a partial O-alkylation product of  hydroxyl of polyhydroxystyrene (for example, a 5 to 30 mo!  % O-methylation product, O-(1-methoxy )ethylation product,  O-(1-ethoxy )ethylation product, O-2-tetrahydropyranylation  product, O-(t-butoxycarbonyl)methylation product, etc.), an  O-acylation product thereof (for example, a 5 to 30 mo! %  O-acetylation product, O-(t-butoxy)carbonylation product,  etc.), a styrene-maleic anhydride copolymer, a styrene-hy› droxystyrene copolymer, an a-methylstyrene-hydroxysty› rene copolymer, a carboxylated methacrylic resin or its  derivative, or a polyvinyl alcohol derivative. However, the  alkali-soluble resins are not limited to these.  Preferred alkali-soluble resins are a novolak resin, an  o-polyhydroxystyrene, a m-polyhydroxystyrene, a p-polyhy- droxystyrene, a copolymer of these polyhydroxystyrenes, an  alkylated polyhydroxystyrene, a partial O-alkylation product  or O-acylation product of polyhydroxystyrene, a styrene› hydroxystyrene copolymer and an a-methylstyrene-hy› droxystyrene copolymer.  Especially in the present invention, resins having a  hydroxystyrene structure are preferred. Among various  hydroxystyrene structures, a m-hydroxystyrene structure is  most preferred.  The above novolak resin can be obtained by addition con- densation of a given monomer as a main component with an  aldehyde conducted in the presence of an acid catalyst.  The weight average molecular weight of the alkali-soluble  resin is 2000 or greater, preferably from 5000 to 200,000 and  more preferably 5000 to 100,000. Herein, the weight average  molecular weight is in terms of polystyrene molecular weight  measured by gel permeation chromatography (GPC).  In the present invention, two or more types of alkali- soluble resins (C) may be used in combination.  The content of alkali-soluble resin (C), based on the total  solids of the composition, is generally in the range of 40 to 97  mass %, preferably 60 to 90 mass %.  [ 4] Acid Crosslinking Agent Capable of Crosslinking with  the Alkali-Soluble Resin by the Action of an Acid  The negative actinic-ray- or radiation-sensitive resin com› position of the present invention may further contain a  crosslinking agent (D).  Any crosslinking agent can be used as long as it is a com› pound capable of crosslinking with the resin soluble in an  alkali developer by the action of an acid. However, com› pounds (1) to (3) below are preferred.  (1) A hydroxymethylated form, alkoxymethylated or acy- loxymethylated form of phenol derivative.  (2) A compound having an N-hydroxymethyl group, an  N-alkoxymethyl group or an N-acyloxymethyl group.  (3) A compound having an epoxy group.  The alkoxymethyl group preferably has 6 or less carbon  atoms, and the acyloxymethyl group preferably has 6 or less  carbon atoms.  The negative actinic-ray- or radiation-sensitive resin com› position of the present invention may contain an alkali› soluble resin (C) and further according to necessity a  crosslinking agent (D). The alkali dissolution rate of the  alkali-soluble resin (C) as measured in a 0.261 N tetramethy- !ammonium hydroxide (TMAH) (23° C.) is preferably 2  mn/sec or higher, especially preferably 20 mn/sec or higher.  Hereinafter, this resin may also be referred to as "alkali› soluble resin."  [3] Resin Soluble in an Alkali Developer  The content ofresin (B) in the composition of the present  invention based on the total solids thereof is preferably in the  range of 5 to 99.9 mass%, more preferably 50 to 95 mass%  and most preferably 60 to 93 mass %.  In the above specific examples, tBu represents a t-butyl  group.  OH  R-30  v:t  R-29  R-28  -continued  OH  R-27 