A submicrometer megabit DRAM process technology using trench capacitors

This paper describes guidelines for developing a 1-4-Mbit DRAM process, and device/process technologies for fabricating an experimental 1-Mbit DRAM. A single transistor cell combined with a trench capacitor and on-chip ECC technologies has the potential to realize a cell size of 10 µm²without degrading soft error immunity. A depletion trench capacitor, submicrometer n-well CMOS process, Mo-poly gate, and submicrometer pattern formation technologies are developed, and an experimental 1-Mbit DRAM with a cell size of 20 µm²is successfully developed by using these technologies.