Alicyclic polymers for 193 nm resist applications: Synthesis and characterization

A series of new alicyclic polymers designed for use as 193 nn photoresist materials has been synthesized and characterized. These resins are based on cycloaliphatic co- and terpolymers of 2-methylpropylbicyclo[2.2.1]hept-5-ene-2-carboxylate (trivial name, carbo-tert-butoxy norbornene), bicyclo[2.2.1]hept-5-ene-2-carboxylic acid (trivial name, norbornene carboxylic acid), 8-methyl-8-carboxytetracyclo[4,4,0.1,(2,5)1(7,10)]dodec-3-ene (trivial name, methyl tetracyclododecene carboxylic acid), 5-(hydroxymethyl)-2-norbornene-2-methanol, and maleic anhydride, which were synthesized by free radical, Pd(II)-catalyzed addition, and ring-opening metathesis polymerization techniques. The polymers derived from ring-opening metathesis polymerization were hydrogenated to provide another member of this group of materials. The polymers are soluble in common organic solvents and have glass transition temperatures ranging from less than 60 degrees C to higher than 250 degrees C depending on their specific structure and mode of polymerization. The low absorption pf these polymers at 193 nm wavelength and their high resistance to reactive ion etching make these attractive candidates for 193 nm resist applications.