Non-Linear I-V Characteristics of TiOy Film by Optimizing Thickness and Trap Density for Selector-Less ReRAM

The non-linear current voltage (I-V) characteristics in low-resistance state (LRS) of resistive random access memory is the most important device parameter for cross-point memory applications. An ultrathin TiOy tunnel barrier can significantly improve non-linear characteristics of resistive random access memory. Based on mathematical modeling, we verified that direct tunneling and trap assisted tunneling of TiOy layer are dominant in low voltage regime and high voltage regime, respectively. To maximize non-linearity, we need to reduce direct tunneling at low voltage by increasing film thickness and increase trap assisted tunneling at high voltage by increasing trap density.