Ferroelectric memory devices and method of using ferroelectric capacitors
US5764561A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 15, 1996 |
| Grant date | Jun 9, 1998 |
| Priority date | — |
| Expiry date | Nov 15, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/22
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A ferroelectric memory device has a ferroelectric memory capacitor with a hysteresis characteristic adapted to store either a first memory content corresponding to a first polarization condition or a second memory content corresponding to a second polarization condition when there is no applied voltage. A load capacitor is connected in series with the memory capacitor at least at a readout time when the content of the memory capacitor is read out with a readout voltage applied to this series connection. The readout voltage has a polarity different from that of the voltage which will result in the first polarization condition. The memory content of the memory capacitor is determined from the partial voltage generated across the memory capacitor when the readout voltage is applied. A rewrite voltage is applied to the memory capacitor for recovering the polarization condition corresponding to the memory content. The voltage generated across the memory capacitor, when the content of the memory capacitor is read out while the memory capacitor is in a fully charged polarization condition, is zero or of the same polarity as the rewrite voltage for recovering the first polarization conditi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.