A novel nanoscale-crossbar resistive switching memory using a copper chemical displacement technique

Nanoscale-crossbar electrochemical-metallization (ECM) type resistive-switching random access memory (ReRAM) is considered promising candidates for next-generation non-volatile memory. However, performing nanoscale patterning with traditional Cu-based ECM ReRAM is quite challenging, because Cu is difficult to control and pattern using lithography and etching. In this study, a nanoscale Cu-based ReRAM with a Si3N4-SiO2 bi-layer was fabricated successfully through a novel Cu chemical displacement technique (Cu-CDT). Compared with other conventional Cu deposition techniques, the Cu-CDT exhibits numerous advantages including simplicity, low-temperature fabrication, low cost, and high displacement selectivity between poly-Si and the Si3N4-SiO2 bi-layer. Moreover, the developed nanoscale-crossbar Cu-CDT ReRAM device demonstrated stable switching and remarkable high-temperature data retention. Therefore, the Cu-CDT is an effective approach for overcoming Cu etching and patterning limitations.