Novel polymers for photoresist and photoresist compositions using the same

#The present invention relates to photoresist monomers, polymers formed therefrom, and photoresist compositions containing same, more specifically, photoresist monomers, polymers and a photoresist compositions suitable for photolithography processes employing DUV (deep ultraviolet) light sources such as KrF (249 nm) and ArF(193 nm); EUV; VUV; E-beam; ion-beam; and X-ray.

#Recently, chemical amplification type DUV photoresists have been investigated in order to achieve high sensitivity in minute image formation processes for preparing semiconductor devices. Such photoresists are prepared by blending a photoacid generator and matrix resin polymer having acid labile group.

#According to the reaction mechanism of such a photoresist, the photoacid generator generates acid when it is illuminated by a light source, and the main chain or branched chain of the resin is reacted with the generated acid to be decomposed or crosslinked. The polarity change of the resin induces solubility differences between the exposed portion and unexposed portion in the developing solution, to form a predetermined pattern.

#Example 1:

#Synthesis of poly(cis-5-norbornene-endo-2,3-dicarboxylic anhydride/tert-butyl 5-norbornene-2-carboxylate/maleic anhydride/mono-methyl cis-5-norbornene-endo-2,3-dicarboxylate/5-norbornene-2-carboxylic acid)

#Maleic anhydride (1.0 mole), cis-5-norbornene-endo-2,3-dicarboxylic anhydride (0.2 mole), mono-methyl cis-5-norbornene-endo-2,3-dicarboxylate (0.15 mole) and tert-butyl-5-norbornene-2-carboxylate (0.65 mole) are dissolved in tetrahydrofuran. Then, 0.5 to 10 g of AIBN (azobisisobutyronitrile) as a polymerization initiator is added thereto, and the resultant mixture is reacted at about 60-70° C. for 4 to 24 hours under nitrogen or argon atmosphere. The polymer thus obtained is precipitated from ethyl ether or hexane, and dried to obtain the compound represented by the following Chemical Formula 101. 11