Resistive random-access memory
| Computer memory and data storage types |
|---|
| Volatile |
| Non-volatile |
Resistive Random Access Memory (RRAM) is a new non-volatile memory type being developed by Sharp, Samsung, Fujitsu, Spansion, Macronix, Winbond and other companies.[citation needed]
Different forms of RRAM have been disclosed, based on different dielectric materials, spanning from perovskites to transition metal oxides to chalcogenides. Even silicon dioxide has been shown to exhibit resistive switching as early as 1967.[1]
The basic idea is that a dielectric, which is normally insulating, can be made to conduct through a filament or conduction path formed after application of a sufficiently high voltage. The conduction path formation can arise from different mechanisms, including defects, metal migration, etc. Once the filament is formed, it may be reset (broken, resulting in high resistance) or set (re-formed, resulting in lower resistance) by an appropriately applied voltage. Recent data suggest that probably many current paths, rather than a single filament, are involved.[2]
On April 30, 2008 HP announced a Memristor, a fundamentally new circuit element that is another possible demonstration of RRAM.
Papers at the IEDM Conference in 2007 suggested for the first time that RRAM exhibits lower programming currents than PRAM or MRAM without sacrificing programming speed, retention or endurance.[3]
References
- ^ D. R. Lamb and P. C. Rundle, "A non-filamentary switching action in thermally grown silicon dioxide films", Br. J. Appl. Phys. 18, 29-32 (1967)
- ^ D. Lee et al, "Resistance switching of copper doped MoOx films for nonvolatile memory applications", Appl. Phys. Lett. 90, 122104 (2007)
- ^ See, for example, K. Tsunoda et al., IEDM Tech. Dig., 767-770 (2007).