Scalable Non-Volatile Memory and Switch Device for High-Density Bipolar ReRAM Applications

Over the last 20 years the demand for high density non-volatile data storage drastically increased as the mobile consumer device market rapidly expanded. Even today mobile applications are starting to demand evergrowing storage space using the least power. In general, every storage memory device is composed of a memory and switch element. Considering next generation memories such as ReRAM, oxide based materials can be considering a natural transition from Si based devices since it is also usually an oxide based material. Among several devices that could add more function, oxide based devices have been kept in focus because of its possibility of emulating organic brain functions and reconfigurable functions on Si circuits in addition to basic storage operations. Although research on ReRAM has continued to be reported, a reliable memory performance has not yet been presented, because of lacking material architecture and an insufficient understanding of the switching mechanism. In this presentation, a reliable memory device made from Ta2O5-x/TaO2-x bi-layered structure and an oxide based switch device will be proposed. Figure 1 shows the d.c. I-V sweep curves for different cell-size device. There is little size dependence from 0.5×0.5 um to 50×50 um. However, at cell size of 30×30 nm, there is a sudden shift to lower in switching current.