Study of the Robust Stack Cell Capacitor Structure using Double Mold Oxide (DMO) Technology for a Gigabit-Density DRAM and beyond

The robust stack storage node structure for a gigabit-density DRAM device requires improvements in the process structure and the process conditions to avoid the electrical failure during DRAM-cell operation. First of all, the thermo-mechanical stress between the storage nodes, the stable node frame property, and the wet etching process should be improved. We show that optimized process conditions are essential to making a robust storage node structure. Furthermore, in this paper, a novel double mold oxide (DMO) technology is proposed to eliminate the electrical short failure between storage nodes. With the DMO structure, the surface area of the stack cell storage node can be enlarged without electrical short failure between the storage nodes. KCI Citation Count: 1