Novel stacked capacitor technology for 1 Gbit DRAMs with CVD-(Ba,Sr)TiO/sub 3/ thin films on a thick storage node of Ru

Abstract

Simple stacked cell capacitors for 1 Gbit DRAMs have been constructed with a thick storage node of ruthenium (Ru) and high dielectric constant CVD-(Ba,Sr)TiO/sub 3/ films of equivalent oxide thickness teq=0.50 nm with an excellent step coverage. A storage capacitance of 30 fF/cell was shown to be realized for storage nodes 0.24 /spl mu/m wide, 0.60 /spl mu/m deep, and 0.20 /spl mu/m high, with a charge loss below 19% of the initial stored charge during a pause-refresh time of 10 s in 1 Gbit DRAMs.