| abstract |
(57) [Problem] To provide a norbornene-based copolymer for a photoresist, a method for producing the same, and a photoresist composition containing the same. SOLUTION: 5-norbornene-2-alkane-1, A 3-dione compound and a norbornene derivative are used as an essential comonomer, and a ketal compound which is a derivative of the 5-norbornene-2-alkane-1,3-dione compound is selectively added thereto. Norbornene-based copolymer for photoresist and a photoresist composition containing the same. According to this, not only high transparency and etching resistance at 193 nm but also pK a is adjusted, the resolving power can be increased by a remarkable dissolution rate difference between the exposed part and the non-exposed part. In addition, since the compound has a highly hydrophilic diketone functional group, it exhibits excellent substrate adhesive strength. It can be used very effectively as a photoresist material for use. |