Title :
A ferroelectric DRAM cell for high-density NVRAMs
Author :
Moazzami, Reza ; Hu, Chenming ; Shepherd, William H.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., California Univ., Berkeley, CA, USA
Abstract :
The operation of a ferroelectric DRAM (dynamic random access memory) cell for nonvolatile RAM (NVRAM) applications is described. Because polarization reversal only occurs during nonvolatile store/recall operations and not during read/write operations, ferroelectric fatigue is not a serious endurance problem. For a 3-V power supply, the worst-case effective silicon dioxide thickness of the unoptimized lead zirconate titanate film studied is less than 17 AA. The resistivity and endurance properties of ferroelectric films can be optimized by modifying the composition of the film. This cell can be the basis of a very-high-density NVRAM with practically no read/write cycle limit and at least 10/sup 10/ nonvolatile store/recall cycles.<>
Keywords :
DRAM chips; ferroelectric storage; lead compounds; random-access storage; zirconium compounds; 17 A; 3 W; PZT-SiO/sub 2/; PbZrO3TiO3-SiO2; ferroelectric DRAM cell; ferroelectric fatigue; ferroelectric films; high-density NVRAMs; nonvolatile recall operations; nonvolatile store operations; polarization reversal; read operations; write operations; DRAM chips; Fatigue; Ferroelectric films; Ferroelectric materials; Nonvolatile memory; Polarization; Power supplies; Random access memory; Read-write memory; Silicon compounds;
Journal_Title :
Electron Device Letters, IEEE
