Progressive and Stable Synaptic Plasticity with Femtojoule Energy Consumption by the Interface Engineering of a Metal/Ferroelectric/Semiconductor. Issue 22 (24th May 2022)

• Record Type: Journal Article
• Authors: Kim, Sohwi; Yoon, Chansoo; Oh, Gwangtaek; Lee, Young Woong; Shin, Minjeong; Kee, Eun Hee; Park, Bae Ho; Lee, Ji Hye; Park, Sanghyun; Kang, Bo Soo; Kim, Young Heon
• Is Part Of: Advanced science. Volume 9:Issue 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-24
• Subjects: energy efficiency -- linearity -- low reading current -- short operation time -- symmetry; Science -- Periodicals; 505
• DOI: 10.1002/advs.202201502
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: In the era of "big data, " the cognitive system of the human brain is being mimicked through hardware implementation of highly accurate neuromorphic computing by progressive weight update in synaptic electronics. Low‐energy synaptic operation requires both low reading current and short operation time to be applicable to large‐scale neuromorphic computing systems. In this study, an energy‐efficient synaptic device is implemented comprising a Ni/Pb(Zr0.52 Ti0.48 )O3 (PZT)/0.5 wt.% Nb‐doped SrTiO3 (Nb:STO) heterojunction with a low reading current of 10 nA and short operation time of 20–100 ns. Ultralow femtojoule operation below 9 fJ at a synaptic event, which is comparable to the energy required for synaptic events in the human brain (10 fJ), is achieved by adjusting the Schottky barrier between the top electrode and ferroelectric film. Moreover, progressive domain switching in ferroelectric PZT successfully induces both low nonlinearity/asymmetry and good stability of the weight update. The synaptic device developed here can facilitate the development of large‐scale neuromorphic arrays for artificial neural networks with low energy consumption and high accuracy. Abstract : In this study, an energy‐efficient synaptic device based on a Ni/Pb(Zr0.52 Ti0.48 )O3 (PZT)/Nb‐doped SrTiO3 heterojunction with a low reading current and a short operation time that results from the interface engineering between top electrode and PZT is implemented. Furthermore, PZT ferroelectric with multi‐domain configurations can enable electrical modulation gradually and stably, leading to linear/symmetric synaptic plasticity with small variability.