Real-Time Observation of the Electrode-Size-Dependent Evolution Dynamics of the Conducting Filaments in a SiO₂ Layer

Abstract

Conducting bridge random access memory (CBRAM) is one of the most promising candidates for future nonvolatile memories. It is important to understand the scalability and retention of CBRAM cells to realize better memory performance. Here, we directly observe the switching dynamics of Cu tip/SiO/W cells with various active electrode sizes using in situ transmission electron microscopy. Conducting filaments (CFs) grow from the active electrode (Cu tip) to inert electrode (W) during the SET operations. The size of the Cu tip affects the electric-field distribution, the amount of the cation injection into electrolyte, and the dimension of the CF. This study provides helpful understanding on the relationship between power consumption and retention of CBRAM cells. We also construct a theoretical model to explain the electrode-size-dependent CF growth in SET operations, showing good agreement with our experimental results.

Bridging Biological and Artificial Neural Networks with Emerging Neuromorphic Devices: Fundamentals, Progress, and Challenges

“…[99,146] Under electrical bias, Ag or Cu atoms are oxidized to ions, which migrate along the electric field and then are reduced to neutral atoms in the electrolyte, forming a metallic filament(s) and suddenly increase the conductance of the device. [99,146] Under electrical bias, Ag or Cu atoms are oxidized to ions, which migrate along the electric field and then are reduced to neutral atoms in the electrolyte, forming a metallic filament(s) and suddenly increase the conductance of the device.…”

Direct Evidence of Lithium Ion Migration in Resistive Switching of Lithium Cobalt Oxide Nanobatteries

“…Although transmission electron microscopy (TEM) is a useful method to observe the mechanisms for ECM (involving metal cations), valence change memories, and thermochemical unipolar systems, it requires sample thinning processes, which may partly destroy the regions of interest and thus prevent detailed spatial studies of the light Li + cations. Thus, SIMS is chosen here as the technique to study the elements composing Li x CoO 2 .…”

Bacteriophages and Their Immunological Applications against Infectious Threats

“…Endolysins derived from Gram-positive-infecting phages have a modular domain structure that shows a variety in its architecture [86]. It is composed of two highly conservative domains: a N-terminal catalytic domain and a C-terminal bacterial wall-binding domain, connected by a linker [87].…”

“…All endolysins are hydrolases, except for transglycolases; amidases and muramidases are the most represented classes [88]. The C-terminal domain specifically binds ligands on the bacterial wall, tethering the lysin to the proteoglycan: even if the number of binding domains varies between endolysins [86], the affinity is almost as strong as antigen-antibody binding [89]. …”

“…For example, chimeric enzymes (chimeolysins) can be obtained by substitution or addition of heterologous binding domains to expand the bacteriolytic spectrum outside the native endolysins species specificity [86, 91]. Further improvements to endolysin properties have been obtained so far after fusion to a peptide or a protein domain of nonendolysin origin (artilysins) [92].…”