Impact of titanium doping and pulsing conditions on the analog temporal response of hafnium oxide based memristor synapses

Abstract

Hafnium oxide non-volatile memories have shown promise as an artificial synapse in neuromorphic computing architectures. However, there is still a need to fundamentally understand how to reliably control the analog resistance change induced by oxygen ions that partially rupture or re-form the conductive filament. In this work, the impact of measurement conditions (pulse amplitude and pulse width) and titanium dopants on the analog resistance change of atomic layer deposited hafnium oxide memristor synapses are studied. A lower pulse amplitude improves the linearity of resistance change as a function of the number of pulses but results in a smaller memory window. The addition of titanium dopants does not substantively change the analog resistance modulation of hafnium oxide. Density functional theory calculations show that titanium strongly impacts oxygen ion motion in the Hf xTi yO z matrix but does not impact significantly in the HfTi metallic filament. This study demonstrates that the analog characteristic of Hf xTi yO z artificial synapses is largely independent of the titanium doped bulk oxide since the resistance change is primarily controlled by the HfTi metallic conducting filament.

Asymmetric Resistive Switching of Bilayer HfOx/AlOy and AlOy/HfOx Memristors: The Oxide Layer Characteristics and Performance Optimization for Digital Set and Analog Reset Switching

“…Even though our primary goal was to analyze the resistive switching performances of HfO x /AlO y (D1) and AlO y /HfO x (D2) devices, we measured the I – V characteristics of all four devices, especially for the forming (if required), reset, and set operations. As we described in our recently published articles, , we used the optimized test conditions and protocols for all I – V characterizations, including forming and prestabilization of the CFs. We then analyzed the switching performance of all the devices and reported the optimized results.…”

Review on Resistive Switching Devices Based on Multiferroic BiFeO3

“…Furthermore, as reported, the RS process in FTJs, which can reach ˜nA, consumes much less energy in terms of current than the comparison VCM [79]. Additionally, the doping effect has been demonstrated to significantly influence the energy consumption of memristive devices based on various RS mechanisms [80][81][82]. For example, Tan et al [83] demonstrated that the introduction of nickel doping in HfO x can reduce the energy consumption and enhance the multilevel resistance behavior under the same pulse operation.…”

Trade-off between Gradual Set and On/Off Ratio in HfOx-Based Analog Memory with a Thin SiOx Barrier Layer

“…Traditional artificial neural networks based on von-Neuman computing consume significant energy and are facing challenges for data-intensive tasks due to the physical separation of memory and logic processing. , Taking inspiration from biological cognition, neuromorphic computing aims to enable artificial intelligence to perform closer to biological cognition for complex tasks such as self-driving, language translation, pattern and speech recognition, and real-time health monitoring. − …”