Characterization of sputter-deposited (Ba,Sr)TiO/sub 3/ thin films on the sidewalls of fine-patterned electrodes

The dielectric properties of high dielectric constant thin films on the electrode sidewalls were evaluated for the first time, and sputter-deposited (Ba,Sr)TiO/sub 3/ thin films were characterized on the sidewalls of RuO/sub 2/ electrodes patterned down to submicron sizes. A fairly large step coverage around 50% was obtained for (Ba,Sr)TiO/sub 3/. The /spl epsiv//sub r/ value for (Ba,Sr)TiO/sub 3/ films on the sidewalls was the same as that for the films on the top surface, but the leakage current was larger. The (Ba,Sr)TiO/sub 3/ films on the sidewalls were found to be well crystallized, however, the grain size was smaller, and a porous structure was observed by TEM analysis.