Functional neuronal computing systems that support information diversification require high-density memory with selector devices to reduce leakage current in cross-point architectures, which drives us to develop a functional switching layer that operates as three distinct devices, namely non-volatile memory, selector, and synaptic devices, using a GeTe-based single material system. In this study, amorphous Ag-GeTe switching layers are engineered by doping with Te species to achieve either resistive switching (RS) or threshold switching properties. The Ag/Ag-GeTe/Ag memory device exhibits multilevel characteristics via a tunable compliance current approach. By comparison, Ag/Ag-GeTex/Ag selector device provides excellent selectivity (>106) with a very low OFF-current (∼10−11 A). The RS mechanism for memory and selector devices is interrogated by using conductive atomic force microscopy. Moreover, the Ag/Ag-GeTe/Ag RS device mimics a cohort of basic and complex synaptic plasticity properties, including potentiation-depression and four-spike time-dependent plasticity rules that include asymmetric Hebbian, asymmetric anti-Hebbian, symmetric Hebbian, and symmetric anti-Hebbian learning rules. The capability of the synaptic devices to detect image edges is demonstrated by using a convolution neural network. The present work showcases the multi-functionality of Ag-GeTe materials, which will likely emerge as a prominent candidate for high-density cross-point architecture-based neuromorphic computing systems.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea grant funded by the Korean government (No. 2016R1A3B1908249 ) and the Samsung Semiconductor Research Center in Korea University ( IO201211-08116-01 ).
© 2021 The Author(s)
- Amorphous Ag-GeTe
- Convolutional neural network edge detection
- Multilevel resistive switching
- Neuromorphic computing
- Selector device
ASJC Scopus subject areas
- Ceramics and Composites
- Surfaces, Coatings and Films
- Metals and Alloys