A UNIFIED APPROACH TO RESIST MATERIALS DESIGN FOR THE ADVANCED LITHOGRAPHIC TECHNOLOGIES

New resist materials and processes are necessary to pattern less-than- or-equal-to 0.25 mum design rule circuits with advanced deep-UV, X-ray and e-beam lithographic technologies. Chemically amplified positive r esist systems introduced to meet the high sensitivity and resolution r equirements of the deep-uv, e-beam and x-ray exposure tools suffered f rom marginal adhesion, poor etch resistance and deteriorating process performance with post-exposure delay (PED) time. Improved resist syste ms such as those based on materials etoxystyrene-4-t-butoxycarbonyloxy styrene-sulfone) (PASTBSS) terpolymers resolved the adhesion problems and improved the etch resistance and post-exposure delay time stabilit y. Theses resists, however, still required a covercoat for good proces s performance. Additionally, all the current commerical chemically amp lified positive resists show varied degrees of ''foot'' formation on T itanium Nitride and Silicon Nitride substrates and strong linewidth de pendence on PEB temperature (large DELTAlw/-degrees-C). We have develo ped a new multi-component positive chemically amplified resist called ARCH (Advanced Resist CHemically Amplified), that in addition to exhib iting excellent resolution with deep-uv, x-ray and e-beam exposures, d isplays no noticeable foot on Titanium Nitride, Silicon Nitride and BP SG substrates. Initial results with deep-uv lithography also indicate that linewidth dependence on post-exposure bake (PEB) is minimal. This chemically amplified resist system exhibits linear 0.25 mum resolutio n with a GCA XLS excimer laser stepper (0.53 NA, 248 nm) and 0.14 mum resolution with a pulsed laser point source proximity print x-ray step per (lambda centered at 1.4 nm) and 0.1 mum resolution with a JEOL JBX -5DII e-beam exposure system (at 50 keV).