Abstract
In this work, resistive switching and synaptic behaviors of a TiO2/Al2O3 bilayer device were studied. The deposition of Pt/Ti/TiO2/Al2O3/TiN stack was confirmed by transmission electron microscopy (TEM) and energy X-ray dispersive spectroscopy (EDS). The initial state before the forming process followed Fowler-Nordheim (FN) tunneling. A strong electric field was applied to Al2O3 with a large energy bandgap for FN tunneling, which was confirmed by the I-V fitting process. Bipolar resistive switching was conducted by the set process in a positive bias and the reset process in a negative bias. High-resistance state (HRS) followed the trap-assisted tunneling (TAT) model while low-resistance state (LRS) followed the Ohmic conduction model. Set and reset operations were verified by pulse. Moreover, potentiation and depression in the biological synapse were verified by repetitive set pulses and reset pulses. Finally, the device showed good pattern recognition accuracy (~88.8%) for a Modified National Institute of Standards and Technology (MNIST) handwritten digit database in a single layer neural network including the conductance update of the device.
Highlights
Bilayer Resistors for Synaptic Device.Resistive switching was observed from an SiOx layer in the 1960s.Resistance-based memory is considered a computing element and a storage element.Resistance-based memories are largely classified into three types, with each memory type having its advantages and disadvantages
HfO2 /Al2 O3 bilayer device on TiN electrode can increase the nonlinearity of an I-V curve in the low-resistance state for high-density memory [25]
We investigated resistive switching characteristics and conduction mechanisms, including initial state before forming lowresistance state (LRS) and high-resistance state (HRS)
Summary
Bilayer Resistors for Synaptic Device.Resistive switching (memristive effect) was observed from an SiOx layer in the 1960s.Resistance-based memory is considered a computing element and a storage element.Resistance-based memories are largely classified into three types, with each memory type having its advantages and disadvantages. Phase-change random-accessmemory (PcRAM) [2] has an intermediate character between dynamic random-access memory (DRAM) and NAND flash in terms of latency and memory density. It is used for storage class memory (SCM). Interface type RRAM has good variability with multi-level cell (MLC) It has a slow switching speed [7]. HfO2 /Al2 O3 bilayer device on TiN electrode can increase the nonlinearity of an I-V curve in the low-resistance state for high-density memory [25]. A lot of resistive switching behaviors including gradual and abrupt switching have been
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
