A forming-free WO x resistive memory using a novel self-aligned field enhancement feature with excellent reliability and scalability

A thorough study of the switching mechanism for WO x ReRAM gives clues about how to improve its performance and reliability. Consequently, a 60nm WO x ReRAM is achieved with excellent characteristics - 50ns fast switching, 10 6 cycling endurance, large MLC window, low read disturb of > 10 9 , and excellent 150°C/2,000Hrs data retention. Furthermore, the oxidation of the TiN barrier into an insulating TiNO X causes the WO x to protrude above the remaining TiN and thus creates field enhancement. The boosted electric field eliminates the need for an initial forming step.