A high-C capacitor (20.4 fF/ mu m/sup 2/) with ultrathin CVD-Ta/sub 2/O/sub 5/ films deposited on rugged poly-Si for high density DRAMs

Abstract

Storage capacitors integrating ultrathin chemical vapor deposited-Ta/sub 2/O/sub 5/ (10 to 15 nm thick) on rapid thermal nitrided rugged polycrystalline silicon electrodes are proposed for 256 Mb stacked dynamic random access memory applications. The unique combination of this high dielectric constant material with a rugged hemispherical grain silicon electrode allows the manufacture of the ultra high capacitance (20.4 fF/ mu m/sup 2/) stacked structures needed beyond 64 Mb.<>