Non-volatile memory (NVM) will play a decisive role in the development of the next-generation of electronic products. Therefore, the development of next-generation NVM is urgent as widely applied flash memory is facing its physical limit. Among various next-generation NVMs, Resistive Random Access Memory (RRAM) is a promising candidate for future memory due to its high-efficiency, high-speed and energy-saving characteristics. In recent years, continuous improvement and in-depth investigation in both materials and electrical switching mechanisms have not only lead to a breakthrough in the performance of digital NVM, but also lead to other possible memory functionality. This paper describes new findings and perspectives on various RRAM devices with different laminated structures and materials, and classifies RRAM into four categories according to different resistive switching mechanisms, from which the four elements are (1) anion-type RRAM: redox reaction and migration of oxygen ions, (2) cation-type RRAM: redox reaction and migration of cation ions, (3) carbon-based RRAM: the stretch of CC bond lengths due to oxygen and hydrogen dual ions, (4) oxide-based electrode: oxygen accumulation in oxide-based electrode.

Read full text on ScienceDirect

DOI: 10.1016/j.mattod.2015.11.009