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having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). 

[0030] Incidentally, the term "actinic rays" or "radiation" as used herein refers to, for example, a bright line spectrum of mercury lamp, far ultraviolet rays represented by excimer laser, extreme ultraviolet rays (EUV light), X-rays, an elec› tron beam, or the like. As used herein, the term "light" means actinic rays or radiation. Furthermore, unless otherwise indicated, the term "exposure" as used herein includes not only exposure to a mercury lamp, far ultraviolet rays rep› resented by excimer laser light, X-rays, EUV light, or the like but also lithography with particle beams such as an electron beam and an ion beam. 

[0031] The actinic ray-sensitive or radiation-sensitive resin composition of the present invention (hereinafter, simply referred to as "composition" or "composition of the present invention".) is an actinic ray-sensitive or radiation› sensitive resin composition including (A) a polymer com› pound having a structure in which a hydrogen atom of a phenolic hydroxyl group is substituted by a group repre› sented by General Formula (I) described below, and (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation. 

[0032] The composition of the present invention is pref› erably for electron beam or extreme ultraviolet exposure. 

[0033] The composition of the present invention may be a negative chemically amplified resist composition or may be a positive chemically amplified resist composition. 

[0034] A pattern simultaneously providing high resolution (for example, high resolving power, excellent pattern profile, and low line edge roughness (LER)), and good dry etching resistance can be formed by forming a resist film using the composition of the present invention containing a specific polymer compound (A). Although the reason is not clear, it is estimated as follows. 

[0035] First, a phenolic hydroxyl group of the polymer compound (A) has been protected by a group represented by General Formula (I), but this group contains an alicyclic group having a relatively high glass transition point (Tg). Therefore, it is considered that a Tg of the polymer com› pound (A) itself, or a Tg of a resist film formed from a composition containing the polymer compound (A) also becomes higher, and as a result, dry etching resistance is improved. 

[0036] Moreover, it is considered that high resolving power, excellent pattern profile, small LER, and the like are achieved because the diffusion of an acid generated from a later-described compound (B) (acid generator) is inhibited as a Tg becomes higher. 

[0037] Hereinafter, the actinic ray-sensitive or radiation› sensitive resin composition of the present invention will be described in detail. 

[0038] [1] (A) Polymer Compound 

[0039] The actinic ray-sensitive or radiation-sensitive resin composition of the present invention contains (A) a polymer compound having a structure in which a hydrogen atom of a phenolic hydroxyl group is substituted by a group represented by the following General Formula (I) (herein› after, also referred to as "polymer compound (A)"). 

[0040] The present invention uses, as a main component, a polymer compound which contains phenolic hydroxyl groups and in which a portion of the phenolic hydroxyl groups is substituted by a group represented by the follow› ing General Formula (I). 

[0041] In General Formula (I), A$_{1 }$ represents an alicyclic group having 3 to 12 carbon atoms which may have a heteroatom. R$_{1 }$ and R$_{2 }$ each independently represent a hydrocarbon group. R$_{1 }$ and R$_{2 }$ may be bonded to each other to form a ring. * indicates a binding site to an oxygen atom of the phenolic hydroxyl group. 

[0042] The site which is substituted by a group repre› sented by General Formula (I) is a part having a function of controlling the developability of a polymer compound con› taining a repeating unit having a phenolic hydroxyl group. The structure in which a hydrogen atom of a phenolic hydroxyl group is substituted by a group represented by General Formula (I) is decomposed by the action of an acid to generate a phenolic hydroxyl group. 

[0043] The group represented by General Formula (I) will now be described. 

[0044] In General Formula (I), A$_{1 }$ represents an alicyclic group having 3 to 12 carbon atoms which may have a heteroatom and which may have a double bond. 

[0045] Examples of such an alicyclic group include a monocyclic cycloalkyl group and a bridged cycloalkyl group. 

[0046] Examples of the monocyclic cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclo› heptyl group, a cyclohexyl group, a cyclopentyl group, a cyclooctyl group, a cyclononyl group, a cyclodenyl group, a cycloundenyl group, and a cyclododecanyl group. The monocyclic cycloalkyl group is preferably a cyclohexyl group or a cyclopentyl group. 

[0047] The bridged cycloalkyl group is, for example, a group containing a structure such as a bicyclo structure, a tricyclo structure, or a tetracyclo structure, and specific examples thereof include a bicyclobutyl group, a bicyclo› hexyl group, a bicycloheptyl group, a bicyclooctyl group, a bicyclononyl group, a bicyclodecanyl group, a bicycloun› decanyl group, a bicyclododecanyl group, an adamantyl group, a decalin group, an isobornyl group, a norbornyl group, a cedrol group, a camphanyl group, an a-pine! group, a tricyclodecanyl group, a tetracyclododecyl group, and androstanyl group. Among these, preferred are an adamantyl group, a decalin group, a norbornyl group, a cedrol group, a bicyclohexyl group, a bicycloheptyl group, a bicyclooctyl group, a bicyclodecanyl group, a bicyclododecanyl group, and a tricyclodecanyl group. More preferred is an adamantyl group from the viewpoint of dry etching resistance. 

[0048] Further, other examples of the alicyclic group include a cyclohexenyl group, a cyclohexadienyl group, a cyclopentenyl group, a cyclopentadienyl group, a bicy› clooctenyl group, and a bicyclotridecenyl group. 

[0049] Further, a part of carbon atoms in the monocyclic or bridged cycloalkyl group may be substituted, for example, by a heteroatom such as an oxygen atom or a sulfur atom. 

[0050] The alicyclic group represented by A$_{1 }$ is preferably a bridged cycloalkyl group, because the effect of the present invention (in particular, dry etching resistance) is superior. 

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(I) 

