Bi2O2Se-based CBRAM integrated artificial synapse

Dharmendra Verma; Tsung-Cheng Chen; Bo Liu; Chao-Sung Lai

doi:10.1016/j.heliyon.2023.e22512

Bi₂O₂Se-based CBRAM integrated artificial synapse

Heliyon. 2023 Nov 17;9(12):e22512. doi: 10.1016/j.heliyon.2023.e22512. eCollection 2023 Dec.

Authors

Dharmendra Verma¹, Tsung-Cheng Chen¹, Bo Liu², Chao-Sung Lai^{1

3

4}

Affiliations

¹ Department of Electronic Engineering, Chang Gung University, Taoyuan 33302, Taiwan.
² Faculty of Information Technology, College of Microelectronics, Beijing University of Technology, Beijing 100124, People's Republic of China.
³ Department of Nephrology, Chang Gung Memorial Hospital, Linkou 33302, Taiwan.
⁴ Department of Materials Engineering, Ming-Chi University of Technology, New Taipei City 24301, Taiwan.

Abstract

Integrating two-dimensional (2D) semiconducting materials into memristor structures has paved the way for emerging 2D materials to be employed in a vast field of memory applications. Bismuth oxyselenide (Bi₂O₂Se), a 2D material with high electron mobility, has attracted significant research interest owing to its great potential in various fields of advanced applications. Here, we explore the out-of-plane intrinsic switching behavior of few-layered Bi₂O₂Se via a cross point device for application in conductive bridge random access memory (CBRAM) and artificial synapses for neuromorphic computing. Via state-of-the-art methods, CVD-grown Bi₂O₂Se nanoplate is applied as a switching material (SM) in an Al/Cu/Bi₂O₂Se/Pd CBRAM structure. The device exhibits ∼90 consecutive DC cycles with a tight distribution of the SET/RESET voltages under a compliance current (CC) of 1 mA, a retention of over 10 ks, and multilevel switching characteristics showing four distinct states at Vread values of 0.1, 0.2, 0.25, and 0.3 V. Moreover, an artificial synapse is realized with potentiation and depression by modulating the conductance. The switching mechanism is explained via Cu migration through Bi₂O₂Se based on HRTEM analysis. The present structure shows potential for future integrated memory applications.

Keywords: 2D material; Artificial synapse; Bi2O2Se; CBRAM; Cross point structure.