Improving Unipolar Resistive Switching Uniformity with Cone-Shaped Conducting Filaments and Its Logic-In-Memory Application

Abstract

Resistive random access memory (RRAM) with inherent logic-in-memory capability exhibits great potential to construct beyond von-Neumann computers. Particularly, unipolar RRAM is more promising because its single polarity operation enables large-scale crossbar logic-in-memory circuits with the highest integration density and simpler peripheral control circuits. However, unipolar RRAM usually exhibits poor switching uniformity because of random activation of conducting filaments and consequently cannot meet the strict uniformity requirement for logic-in-memory application. In this contribution, a new methodology that constructs cone-shaped conducting filaments by using chemically a active metal cathode is proposed to improve unipolar switching uniformity. Such a peculiar metal cathode will react spontaneously with the oxide switching layer to form an interfacial layer, which together with the metal cathode itself can act as a load resistor to prevent the overgrowth of conducting filaments and thus make them more cone-like. In this way, the rupture of conducting filaments can be strictly limited to the tip region, making their residual parts favorable locations for subsequent filament growth and thus suppressing their random regeneration. As such, a novel "one switch + one unipolar RRAM cell" hybrid structure is capable to realize all 16 Boolean logic functions for large-scale logic-in-memory circuits.

Recent Advances of Quantum Conductance in Memristors

“…Similarly, the filaments in V 2 O 5 memristors were recently affirmed by Xue et al [62] to be VO 2 nanochannels (Figure 3b). Such point of view was further verified very recently by Gao et al [64] Figure 2. Such point of view was further verified very recently by Gao et al [64] Figure 2.…”

“…The 1ω and 2ω patterns are considered to be caused by the accumulated charges (i.e., oxygen ions) near the surface and the stoichiometry variation as well as structural deformation (i.e., oxygen-deficient filaments), respectively. [64] Copyright 2018, American Chemical Society. [68] External electric field can attract oxygen ions to the anodic interface, making oxygen vacancies accumulated initially at the cathodic interface.…”

A True Random Number Generator Using Threshold‐Switching‐Based Memristors in an Efficient Circuit Design

“…[1][2][3] While it was initially suggested to the semiconductor field as a promising functional element for storage memory applications, its application fields are now widening to include other applications, such as logic-in-memory, [4][5][6] neuromorphic computing, [7][8][9] and sensory circuits like the nociceptor. [1][2][3] While it was initially suggested to the semiconductor field as a promising functional element for storage memory applications, its application fields are now widening to include other applications, such as logic-in-memory, [4][5][6] neuromorphic computing, [7][8][9] and sensory circuits like the nociceptor.…”

Performance‐Enhancing Selector via Symmetrical Multilayer Design

“…When the DC voltage sweeps back to zero, the filament ruptures at the most vulnerable location and diffuses into dielectrics due to Rayleigh instability ( I CC < 100 µA). When giving a large I CC (over 100 µA), the Ag diffusion capability of oxygen‐rich layer and Joule heating caused by current guarantee the continuity of TS operations (Figure d) . With the filament size goes down to several nanometers or even atomic scale, nano/quantum size effects and Gibbs–Thomson effect could convert the tiny portion of CFs from nanowire to nanoparticles .…”