Observation of Resistive Switching Memory by Reducing Device Size in a New Cr/CrOx/TiOx/TiN Structure

The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/CrO (x) /TiO (x) /TiN structure for the first time. Transmission electron microscope image confirmed a via-hole size of 0.4 A mu m. A 3-nm-thick amorphous TiO (x) with 4-nm-thick polycrystalline CrO (x) layer was observed. A small 0.4-A mu m device shows reversible resistive switching at a current compliance of 300 A mu A as compared to other larger size devices (1-8 A mu m) owing to reduction of leakage current through the TiO (x) layer. Good device-to-device uniformity with a yield of > 85 % has been clarified by weibull distribution owing to higher slope/shape factor. The switching mechanism is based on oxygen vacancy migration from the CrO (x) layer and filament formation/rupture in the TiO (x) layer. Long read pulse endurance of > 10(5) cycles, good data retention of 6 h, and a program/erase speed of 1 A mu s pulse width have been obtained.