Fig. 1 (a) Device structure of self-rectifying Pt/HZO/TiN device. (b) Typical I-V characteristics in DC-sweeping mode. (c) The memory window with applied positive voltages. (d) The read currents distribution under ±3V.
Results and discussion: Fig. 1b shows 20 I-Vhysteresis loops of Pt/HZO/TiN device in DC sweeping mode. Notably, no electroforming and no compliance current is needed to trigger the reproducible switching behaviors. The memory window of ~ 104 and rectify ratio of ~ 104 can be obtained with 3 V read voltage. The read currents of high resistance state (HRS) and low resistance state (LRS) are ~ 10 pA and ~ 100 nA, indicating the potential for low-power applications. Fig. 1c and 1d show the memory window with applied positive voltages and the read currents distribution under ±3 V, respectively. These results further confirm the self-rectifying resistive switching behaviors in the proposed Pt/HZO/TiN device. According to a SPICE-based circuit analysis, where the parasitic wire resistance between adjacent cells is estimated as Rwire = 10 Ω/cell, the rectify ration of 104 and memory window of 104 are able to support passive crossbar array integration scale up to Mb-level [5,6].