To provide a norbornene copolymer for photoresists, to provide a method for producing the same, and to provide a photoresist composition containing the same.
The norbornene copolymer for photoresists is synthesized by using 5-norbornen-2-alkane-1,3-dione and a norbornene derivative as the essential comonomers, and selectively adding thereto a ketal compound being a derivative of the 5-norbornen-2-alkane-1,3-dione compound. A photoresist composition containing the copolymer is also provided. According to this, it not only has a high transparency to 193 nm and etching resistance but also is controllable in its pKa, so that the resolution can be heightened owing to the marked difference between the dissolution rates at exposed and unexposed areas. Because it has a highly hydrophilic diketone functional group, it can exhibit excellent adhesion to substrates and can be very usefully used as an ArF photoresist material.
MOON BONG SEOK
SHIN JUNG HAN
HAN OUCK
