Selector-less ReRAM with an excellent non-linearity and reliability by the band-gap engineered multi-layer titanium oxide and triangular shaped AC pulse

The effect of oxygen profile control of a multi-layer TiO_x on tunnel barrier characteristics has been investigated to achieve high non-linearity, endurance, and uniformity of a selector-less ReRAM. By optimizing oxygen profile of TiO_x layer in the selector-less ReRAM, non-linearity and a readout margin (low I_LRS at ½V_Read) have been significantly improved compared with 1S1R-type devices and non-linear ReRAMs (Figs. 1-2) [2]-[5]. In addition, AC behaviors of the selector-less ReRAM have been investigated with various AC pulse shape to realize the AC operation of the selector-less ReRAM in cross-point array. Hence, significantly improved AC switching reliability of the selector-less ReRAM was obtained by adopting triangular AC pulse shapes for both set and reset mode.