Daus, Alwin, Lenarczyk, Pawel, Petti, Luisa, Münzenrieder, Niko, Knobelspies, Stefan, Cantarella, Giuseppe, Vogt, Christian, Salvatore, Giovanni A, Luisier, Mathieu and Tröster, Gerhard (2017) Ferroelectric-like charge trapping thin-film transistors and their evaluation as memories and synaptic devices. Advanced Electronic Materials, 3 (12). p. 1700309. ISSN 2199-160X

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Abstract

This work presents a defect charging mechanism in 5-nm-thick amorphous Al2O3 thin-films fabricated on plastic, which leads to multistate memory effects, and thus the realization of synaptic thin-film transistors (TFTs) for neuromorphic applications. First, the Al2O3 thin-films are characterized in metal–insulator–metal stacks. These devices exhibit ferroelectric-like behavior, which is visible in the small-signal capacitance and the surface charge density. Furthermore, the quantum-mechanical simulation of the current–voltage characteristic leads to a physical model with trap charges close to the anode interface where deep-level traps are identified by fitting the experimentally obtained resonant tunneling peaks. The trap charge lifetime and frequency behavior is evaluated in InGaZnO4 TFTs, where the 5-nm-thick Al2O3 layer is employed as gate dielectric. At an operating voltage as low as ±2 V, a charge trapping retention up to ≈3 h and a discernable ON/OFF read-out with a factor >3 at 2 kHz are achieved. When subjected to a train of gate–source voltage pulses, the TFTs show charge integration properties which emulate facilitating and depressing behaviors of biological synapses. These results indicate that thin low-temperature defect-rich metal-oxide dielectrics may be candidates for low-voltage memory applications and neuromorphic circuits on unconventional substrates.

Item Type:	Article
Schools and Departments:	School of Engineering and Informatics > Engineering and Design
Research Centres and Groups:	Sensor Technology Research Centre
Depositing User:	Niko Munzenrieder
Date Deposited:	13 Dec 2017 12:01
Last Modified:	27 Apr 2023 11:10
URI:	http://sro.sussex.ac.uk/id/eprint/72031

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