PROCESS AND DEVICE TECHNOLOGIES FOR 1 GBIT DYNAMIC RANDOM-ACCESS MEMORY CELLS

This article discusses the technological issues involved with continui ng the miniaturization of dynamic random-access memory cells into the gigabit era. Ever-smaller giga-generation dynamic random-access memory cells require three-dimensional high-charge density capacitors with h igh-E insulating films, leading to the need for further improvements i n lithographic resolution for ever-smaller, higher aspect ratio memory cells, and planarization technologies for reducing the memory-cell he ight. This article demonstrates two technologies for meeting these two requirements: high acceleration energy electron-beam lithography and KrF excimer-laser phase-shift photolithography, and plate-wiring merge technology. Metal-insulator-metal 1.6 nm Ta2O5 CROWN capacitors and s ingle Si3N4 spacer OSELO isolation technology for an experimental 1 Gb it dynamic random-access memory chip are also discussed. (C) 1995 Amer ican Vacuum Society.