An Evaluation Of Nitrobenzyl Ester Chemistry For Chemical Amplification Resists

Chemical amplification processes have been reported to be useful in the development of sensitive, high resolution photoresists. Acids, photochemically generated from onium salt precursors, catalytically remove a protective group from substituted hydroxystyrene polymers. Nonionic, acid precursors based on 2-nitrobenzyl ester photochemistry have been developed that have utility in resist applications. Several resist systems capable of imaging via chemical amplification processes have been evaluated in terms of their materials and lithographic properties. Resist with sensitivities ranging from ~15 to 150 mJ/cm2 in the deep-UV region have been prepared and 0.5 μm resolution has been demonstrated.