Multilevel variable resistance memory cell utilizing crystalline programming states
US8363446B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 2009 |
| Grant date | Jan 29, 2013 |
| Priority date | — |
| Expiry date | Dec 31, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2013/0092
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of programming an electrical variable resistance memory device. When applied to variable resistance memory devices that incorporate a phase-change material as the active material, the method utilizes a plurality of crystalline programming states. The crystalline programming states are distinguishable on the basis of resistance, where the resistance values of the different states are stable with time and exhibit little or no drift. As a result, the programming scheme is particularly suited to multilevel memory applications. The crystalline programming states may be achieved by stabilizing crystalline phases that adopt different crystallographic structures or by stabilizing crystalline phases that include mixtures of two or more distinct crystallographic structures that vary in the relative proportions of the different crystallographic structures. The programming scheme incorporates at least two crystalline programming states and further includes at least a third programming state that may be a crystalline, amorphous or mixed crystalline-amorphous state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.