| abstract |
A radiation-sensitive polymer and a chemical amplification resist composition based on the polymer, which can be easily controlled in sensitivity by regulating the content and kind of the carboxylic acid-grafted norbornene derivatives in the matrix polymer and is superior in adherence to substrate and dry etch resistance, so that it can be formed into resist patterns improved in transparency, photosensitivity and resolution by use of KrF or ArF excimer lasers. The polymer is represented by the formula I:wherein, X is an acid-dissociable grafted norbornene derivative selected from the group consisting of the formulas II and III; Y is a carboxylic acid-grafted norbornene derivative represented by the formula IV, and l, m, n and o each are a repeating number not more than 0.5, satisfying the condition that l+m+n+o=l and 0.4<=o<=0.5: |