학술논문

Analog Resistive Switching in BEOL, Ferroelectric Synaptic Weights
Document Type
Periodical
Source
IEEE Journal of the Electron Devices Society IEEE J. Electron Devices Soc. Electron Devices Society, IEEE Journal of the. 9:1275-1281 2021
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Resistance
Ferroelectric devices
Memristors
Junctions
Synapses
memristors
synapse
analog resistor
Language
ISSN
2168-6734
Abstract
A Ferroelectric, two-terminals, analog memristive device is fabricated with a Back-End-Of-Line, CMOS compatible process. A bilayer composed of a ferroelectric material, HfZrO 4 (HZO) and a semiconducting oxide, WO x layer is comprised between two TiN electrodes. The devices demonstrate reversible and remanent resistive switching, with a record endurance (>10 10 switching cycles) and ON/OFF ratio up to 10. The analog resistive switching is obtained, with a cycle-to-cycle reproducibility of 90%. The synaptic behavior is explored with pulses of varying sign, length, or amplitude. For the scheme with constant pulse width the linearity coefficients for the potentiation and depression are −1.4 and 4. The dynamics of the resistive switching is shown to be governed by the ferroelectric domains switching. Finally, temperature dependent transport measurements indicate Ohmic conduction at low bias and Modified Schottky Emission at larger bias. They provide insights on the role of defects and oxygen vacancies in the transport and resistive switching mechanisms.