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substituent group ofR$^{1 }$can include an alkyl group (RsP); an alkyl group including in its skeleton a divalent hetroatom› containing group in place of at least one methylene group of the alkyl group; an alkenyl group having at least one carbon-carbon single bond of the alkyl group substituted with a carbon-carbon double bond; an aryl group (MP); a hydroxy group; a halogen atom and the like. 

[0034] The afore-mentioned Rsp can include a linear, branched, or cyclic alkyl group. The afore-mentioned MP can include an aromatic hydrocarbon group having 12 or less carbon atoms such as a phenyl group, a naphthyl group and the like, and an aromatic heterocyclic group which can include a hetero atom in place of a carbon atom in the ring structure. The substituent group regarding the alkyl group (RsP), the alkenyl group and the aryl group (MP) can include the ones similar as the afore-mentioned alkyl group, the alkeny 1 group and the ary 1 group of R 1 . 

[0035] The substituent group of R $^{1 }$regarding the halogen atom can include a fluorine atom, a chlorine atom, a bromine atom and the like. 

[0036] Here, the total number of carbon atoms in each of R 1 when R 1 has a substituent group is preferably 1 to 20 including the substituent group, more preferably 5 to 15, and especially preferably 6 to 10. 

[0037] As the substituent group of R 1, an alkyl group such as a methyl group and the like, an alkoxy group, a hydroxy group, an aryl group and the like are preferable. 

[0038] As the R1, an alkyl group such as a methyl group, a n-butyl group and the like; and an aryl group such as a phenyl group, a naphthyl group and the like are preferable. 

## (Photosensitive Compound Having an Onium Salt Skeleton) 

[0039] When the photosensitive compounds according to some embodiments of the present invention have an onium salt skeleton, the ones represented by the following formula (2) can be mentioned. Here, the present invention is not limited to these. 

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[0040] In formula (2), Y represents either one of an atom selected from the group consisting of an iodine atom, a sulfur atom, a selenium atom, and a tellurium atom. When Y is iodine atom, n is 2; and when Y is sulfur atom, selenium atom, or tellurium atom, n is 3. 

[0041] R $^{2 }$is independently from each other selected from the same candidates for the afore-mentioned R 1 , and at least one R $^{2 }$in the formula (2) has the Te atom containing group as a substituent group. 2 

[0042] The substituent group of R can include the ones similar to the substituent group of R 1 . 2 

[0043] The substituent group of R , an alkyl group can preferably include an ester group, a hydroxy group, a sulfonyl group, a fluoro group and the like. 2 

[0044] When R includes the Te atom containing group, preferable R 2 is, from the viewpoint of membrane density, solubility and the like, an aryl group having the Te atom containing group. Among the aryl group, a phenyl group 

having the Te atom contammg group, a naphthyl group having the Te atom containing group and the like are more preferable. 

[0045] When R $^{2 }$does not include the Te atom containing group, the preferable R $^{2 }$can include, from the viewpoint of solubility and the like, an alkyl group such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an-butyl group, at-butyl group, a n-pentyl group, a n-hexyl group, a cyclopentyl group, a cyclohexyl group, an adaman› tyl group and the like; an aryl group and the like. 

[0046] Two or more of R $^{2 }$can be bonded to each other to form a ring structure with Y, and the ring structure can include a hetero atom. Here, y+ preferably is not directly bonded with the hetero atom and is bonded with a divalent hydrocarbon group. 2 

[0047] As the cation which is formed by two or more ofR being bonded to each other to form a ring structure with Y, the following can be mentioned for example. In the follow› ing, Y represents either one of a sulfur atom, a selenium atom and a tellurium atom. Here, -R$^{3 }$-Te-R 1 corre› sponds to R 2 having the Te atom containing group repre› sented by formula (1 ). In the following example, a cation having one Te atom containing group was shown, however, the cation can have two or more of the Te atom containing group, and the cation of the present invention is not limited to the following examples. The R 3 can include the afore› mentioned bonding group and the like. 

[0048] The photosensitive compounds of some embodi› ments of the present invention preferably have two or more of the Te atom containing group represented by formula (1), since absorption of electron beam or EUV becomes high. 

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