Very Low-Programming-Current RRAM With Self-Rectifying Characteristics

To resolve the sneak leakage problem and reduce the power consumption in crossbar RRAM arrays, a Cu/Al 2 O 3 /aSi/Ta cell with self-rectifying characteristics is developed. The cell exhibits low operating current ( $\sim $ nA), high ON/OFF ratios ( $> 100\times $ ), and pronounced nonlinearity. The use of low-programming-current RRAM elements avoids the current-driving capability bottleneck of selectors, while the integrated rectifying layer improves the RRAM operation reliability. Endurance of over 500 cycles with $\sim 100$ ON/OFF ratio was achieved without external current compliance. Even at such low programming levels, retention over $10^{4}$ s at 100 °C can still be obtained.