We have investigated the current–voltage characteristics of a resistive switching memory (ReRAM), especially the reproducibility of the switching voltage between an insulating state and a metallic state. The poor reproducibility hinders the practical use of this memory. According to a filament model, the variation of the switching voltage may be understood in terms of the random choice of filaments with different conductivities and lengths at each switching. A limitation of the number of conductive paths is expected to lead to the suppression of the variation of switching voltage. In this study, two strategies for the limitation have been proposed using an anodic porous alumina (APA). The first is the reduction of the number of conductive paths by restriction of the contact area between the top electrodes and the insulator. The second is the lowering of the resistivity of the insulator, which makes it possible to grow filaments with the same characteristics by electrochemical treatments using a pulse-electroplating technique.

No abstract

No abstract

Resistance change random access memory (ReRAM) has been expected to be a next generation non-volatile memory. However, poor reproducibility of threshold voltage at which the dramatic change of the resistivity occurs hinders the practical application. We have attempted to improve the reproducibility of switching voltages using anodic porous alumina whose nanoholes are quite useful to restrict the filament forming area on the basis of the filament model. In this study, we have reported the pore size and film properties dependences of the variation width of the switching voltages. Two kinds of oxide films prepared by oxalic and sulfuric acids with two different anodic times were used as the insulating layer. Contrary to our expectation, just the sulfuric samples indicate good improvement about the switching voltages. Considering that the size of the effective contact area is not enough small against the filament size, the changing the film properties seems to be important for the suppressing the variation of switching voltages.

No abstract