Ferroelectric memory device, a method for read out stored data and a method for standing-by
US5946224A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 23, 1997 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Dec 23, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/22
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
It is an object of the present invention to provide a ferroelectric memory device having a high integration and capable of maintaining nonvolatility. A threshold voltage V.sub.th of a ferroelectric memory element is set at value slightly higher than a voltage -V.sub.1. A voltage 0V is applied as a gate voltage V.sub.G when the stored data is read out. A voltage V.sub.1 is generated at a MOS capacitor C.sub.MOS if the data "High" is stored and the voltage -V.sub.1 is generated at the MOS capacitor C.sub.MOS if the data "Low" is stored. The stored data is read out by detecting a drain current during generation of the voltages. Also, a voltage 0V is applied as the gate voltage V.sub.G when stand-by operation is carried out. In this way, variation of the gate voltage V.sub.G caused by switching ON and OFF of a power source can be prevented. So that, nonvolatility of the ferroelectric memory device can be maintained as a result of preventing spontaneous polarization of a ferroelectric capacitor C.sub.ferro. Further, it is not necessary to provide a circuit for generating a voltage for using read out the data to the ferroelectric memory device. So that, integration of the ferroelectric m…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.