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cyano group) and which does not exhibit acid decompos› ability is preferably 10 to 60 mo!% or more with respect to all of the repeating units in the resin (A) and even more preferably 20 to 50 mo! % from the viewpoint of sufficiently decreasing the solubility with respect to the organic based 5 developer in the exposure portion while sufficiently main› taining the solubility of the unexposed portions and improv› ing the dissolution contrast and from the viewpoint of imparting etching resistance. 10 

In the present invention, the resin (A) may include only one type of repeating unit represented by general formula (1), and may include two or more types. 

The content (in a case where a plurality of types are contained, the total thereof) of the repeating unit represented by the general formula (1) is preferably 70 mo! % or less with respect to all of the repeating units in the resin (A), more preferably 1 to 60 mo! %, and even more preferably 1 to 50 mo! %, and particularly preferably 1 to 40 mo! % from the viewpoint of sufficiently decreasing the solubility with respect to the organic based developer in the exposure portion while sufficiently maintaining the solubility of the unexposed portions and improving the dissolution contrast and from the viewpoint of imparting etching resistance. 

Other Repeating Units 

The resin (A) may further have a repeating unit having a lactone structure. 

The resin (A) may or may not have a repeating unit having a lactone structure resin (A); however, not having the repeating unit is preferable in practice. More specifically, the content of the repeating unit having a lactone structure in the resin (A) is preferably 40 mo! % or less with respect to all of the repeating units in the resin (A), more preferably 25 mo! % or less, even more preferably 10 mo! % or less, ideally O mo! %, that is, not having a repeating unit having a lactone structure is particularly preferable. 

Below, specific examples of the repeating unit having a lactone structure in resin (A) are shown; however, the present invention is not limited thereto. In the formula, Rx represents H, CH$_{3}$ , CH$_{2}$0H, or CFy 

[Chem. 21] 

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[Chem. 22] 

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-continued 

