Extremely Low Leakage Threshold Switch with Enhanced Characteristics via Ag Doping on Polycrystalline ZnO Fabricated by Facile Electrochemical Deposition for an X-Point Selector

Abstract

Leakage current, that causes interferences in the read/write operation, arising from neighboring unselected or half-selected memory cells is considered as one of the main hurdles to be overcome to increase density of cross-point memory arrays. In this work, the common drawbacks for a Ag-based steep-slope threshold switching selector, threshold voltage variability, and poor cycling endurance have been mended. This is achieved by lightly doping the switching layer with Ag instead of implementing the Ag active electrode that acts as a reservoir, which provides unlimited access of Ag to the selector medium. Here, we doped polycrystalline ZnO with Ag, fabricated by facile electrochemical deposition, making a prototypical candidate for the crystalline switching layer. When the amount of Ag is limited by doping, switching characteristics, that is, threshold voltage variability and cycling endurance, are improved. Lastly, different mechanisms causing a threshold switching device to fail are also discussed for the two different test vehicles. It has been found that an unlimited Ag source causes the devices to fail in a short-circuited manner, and a limited Ag source results in devices to fail in an open-circuited manner, after repeated measurements.

Flexible Threshold Switching Based on CsCu2I3 with Low Threshold Voltage and High Air Stability

“…Similarly, the I–V curves, corresponding to the HRS and LRS, and the V th and V hold distributions of ten different devices are shown in Figure S5, reflecting the decent uniformity and repeatability of different devices. Furthermore, a comparison of the SS and V th of our device to the reported values is summarized in Figure i. − The Ag/PMMA/CsCu 2 I 3 /ITO device exhibits a comparable SS of ∼6.2 mV decade –1 and a V th as low as 0.54 V, indicating the possibility of CsCu 2 I 3 -based TSDs for low-power applications with steep SSs.…”

2D-Material-Based Volatile and Nonvolatile Memristive Devices for Neuromorphic Computing

“…Over the last decades, memristive devices based on various bulk materials have been used to fabricate neuromorphic hardware systems, including metal oxides (e.g., HfO 2 , , ZnO, , TiO x , , CuO, , and ZrO 2 , ) and perovskites (e.g., MAPbI 3 , Cs 3 Sb 2 Br 9 , and Cs 3 Cu 2 I 5 ). However, they have some drawbacks, such as high energy consumption and poor scalability, which pose challenges to device integration .…”

“…Constructing an artificial neural network is a common means to realize neuromorphic computing, which has exhibited potential applications in pattern recognition, complex sensing, and other areas. Over the last decades, memristive devices based on various bulk materials have been used to fabricate neuromorphic hardware systems, including metal oxides (e.g., HfO 2 , 27,28 ZnO, 29,30 TiO x , 31,32 CuO, 33,34 and ZrO 2 35,36 ) and perovskites (e.g., MAPbI 3 , 37 Cs 3 Sb 2 Br 9 , 38 and Cs 3 Cu 2 I 5 39 ). However, they have some drawbacks, such as high energy consumption and poor scalability, which pose challenges to device integration.…”

Highly Reliable Electrochemical Metallization Threshold Switch Through Conductive Filament Engineering Using Two‐Dimensional PtSe2 Insertion Layer

“…endurance. [19][20][21][22] Recently, to solve these problems related to the excess diffusion of the active metal ions, ECM TSs in which a Ti or TiN metal buffer layer is inserted between the active electrode and dielectric layer are developed. [22][23][24][25] Due to the low metal ion diffusivity, the metal buffer layer can prevent excessive injection of active metal ions, but interfacial reaction or oxidation of the metal buffer layer may cause unreliable operation.…”

“…The absolute potential of the water dissociation redox reaction decreases as the work function of the inert electrode increases, [ 18 ] so noble metal inert electrode with a large work function leads to large active metal ion concentration within the dielectric layer, resulting in severe variation in threshold voltage and poor endurance. [ 19–22 ] Recently, to solve these problems related to the excess diffusion of the active metal ions, ECM TSs in which a Ti or TiN metal buffer layer is inserted between the active electrode and dielectric layer are developed. [ 22–25 ] Due to the low metal ion diffusivity, the metal buffer layer can prevent excessive injection of active metal ions, but interfacial reaction or oxidation of the metal buffer layer may cause unreliable operation.…”