Resistive switching of the HfO_x/HfO₂ bilayer heterostructure and its transmission characteristics as a synapse

Abstract

In this work, HfOx/HfO2 homo-bilayer structure based resistive random access memory devices were fabricated, and the resistive switching characteristics of the devices were investigated.

Controlled inter-state switching between quantized conductance states in resistive devices for multilevel memory

“…[3][4] It has been proposed that the multiple stable states available in the resistive switches can be used for multilevel storage for ultrahigh density memories. 5 Existence of stable multistates has been demonstrated in resistive switching, [6][7][8][9][10][11][12][13][14] ferroelectric [15][16][17][18][19][20] and phase change [21][22][23][24][25] memory devices. Atomic point contact based QC observed in resistive switching devices has also been demonstrated for memory applications.…”

High performance, electroforming-free, thin film memristors using ionic Na0.5Bi0.5TiO3

“…The ratio of the XPS spectra area between respective elements can qualitatively reflect the relative elemental ratio between different samples. [52][53][54] The detailed plots and fitting of the Na, Bi, Ti and O XPS spectra are shown in Fig. S8 (ESI †).…”

“…4,5 Filamentary-type RS devices based on high-k insulating binary oxides (such as HfO x , TiO 2 , TaO x and NiO) can exhibit high ON/OFF ratios and other advantages. [6][7][8][9][10][11] However, an initial highvoltage electroforming process is needed to enable stable resistive switching operations in many insulating-oxide-materials-based memristors. It is noted that the electroforming process can vary from device to device and/or cell to cell, which limits device scaling and can lead to device failure.…”

Multi-Level Analog Resistive Switching Characteristics in Tri-Layer HfO2/Al2O3/HfO2 Based Memristor on ITO Electrode

“…The physical limitation of the conventional flash memory gives rise to the development of resistive random access memory (RRAM) due to its low power consumption, higher density, and simple structure, which consist of mainly transition metal oxides sandwiched between the top and bottom electrodes [ 1 , 2 , 3 , 4 , 5 , 6 ]. Although, single layer RRAM devices have been found to have uncontrolled filament formation and high switching voltage [ 7 , 8 , 9 ].…”

“…Bilayer RRAM structures already have shown both abrupt and gradual change in conductance under bipolar resistive switching, which has been proposed effective for neuromorphic computing with tunable potentiation and depression. Among different bilayer structures, recently Al 2 O 3 /Ta 2 O 5 , HfO x /HfO 2 , HfO 2 /TiO x , TaO x /Al 2 O 3 , Al 2 O 3 /TiO 2 have been proposed to modulate the RRAM conductance gradually during resistive switching [ 5 , 13 , 17 , 18 , 19 ]. In bilayer structures mostly, oxygen vacancies were found to be located at the bilayer interface, thus the push and pull of oxygen vacancies from the interface mainly controls the resistance of the device during switching.…”