content_image/897608.jpg content_image/897610.jpg content_image/897609.jpg content_image/897613.jpg content_image/897612.jpg content_image/897611.jpg
<img src='content_image/897608.jpg'>

<img src='content_image/897610.jpg'>

<img src='content_image/897609.jpg'>

wherein 

RII- 2 each independently represents an alkyl group, a cycloalkyl group, a halogen atom, an aryl group, an aralkyl group, an alkoxy group or an acyloxy group, and said alkyl group and said aralkyl group each may have an intervening linking group represented by-O-, -S-, --CO$_{2}$-, --CO-, -SO 2 - or -SO-, and when s" represents an integer of2 to 4, a plurality ofRII_$_{2}$s may be the same or difference, and a plurality of RII- $_{2}$s may combine with each other to form a ring structure, 

X $^{1 }$and X$^{2 }$each independently represents a hydrogen atom or an organic group, 

v represents 0 or 1, and 

s" represents an integer of0 to 4. 

7. The positive resist composition as claimed in claim 1, wherein the resin (A) further contains a repeating unit repre- sented by formula (III): 

<img src='content_image/897613.jpg'>

wherein 

R$_{3 }$ to R$_{5 }$ each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group or an alkyl group, and 

X$_{1 }$represents a hydrogen atom or an organic group. 

8. The positive resist composition as claimed in claim 1, wherein at least one ofX in formula (I) contains an alicyclic structure and an aromatic ring structure or both an alicyclic structure and an aromatic ring structure. 

9. The positive resist composition as claimed in claim 1, wherein the non-acid-decomposable group represented by R$_{2 }$ in formula (I) is an alkoxy group. 

10. The positive resist composition as claimed in claim 1, which further comprises a surfactant. 

11. The positive resist composition as claimed in claim 1, wherein the compound (B) includes (Bl) a compound of generating an organic sulfonic acid under the action of actinic rays or radiation. 

12. The positive resist composition as claimed in claim 11, which further comprises (B2) a compound of generating a carboxylic acid under the action of actinic rays or radiation. 

13. The positive resist composition as claimed in claim 1, which further comprises a solvent. 

14. The positive resist composition as claimed in claim 13, wherein the solvent includes a propylene glycol monomethyl ether acetate. 

15. The positive resist composition as claimed in claim 14, wherein the solvent further includes a propylene glycol monomethyl ether. 

16. The positive resist composition as claimed in claim 1, wherein the actinic rays or radiation is selected from the group consisting of electron beam, X-ray or EUV. 

17. A pattern forming method comprising forming a resist film by using the positive resist composition claimed in claim 

1; and exposing and developing said resist film. 

18.A positive resist composition comprising: (A) a resin of which solubility in an alkali developer increases under the action of an acid, the resin containing a repeating unit repre› sented by formula (I) and a repeating unit represented by formula (Ile); and (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation: 

<img src='content_image/897612.jpg'>

wherein 

R$_{1 }$ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a perfluoro group, 

R$_{2 }$ represents a non-acid-decomposable group which con› tains an oxygen atom, and when n represents an integer of2 to 4, a plurality ofR$_{2}$s may be the same or different, 

X represents a hydrogen atom or an organic group, and when m represents an integer of2 to 4, a plurality ofXs may be the same or different, 

m represents an integer of 1 to 4, and 

n represents an integer ofl to 4, provided that 2~n+m~5; wherein formula (Ile) has the following structure: 

<img src='content_image/897611.jpg'>

wherein 

RII_$_{2 }$ represents an alkyl group, a cycloalkyl group, a halogen atom, an aryl group, an aralkyl group, an alkoxy group or an 

