Resistive switching memory performance in oxide hetero-nanocrystals with well-controlled interfaces

Takafumi Ishibe; Yoshiki Maeda; Tsukasa Terada; Nobuyasu Naruse; Yutaka Mera; Eiichi Kobayashi; Yoshiaki Nakamura

doi:10.1080/14686996.2020.1736948

Resistive switching memory performance in oxide hetero-nanocrystals with well-controlled interfaces

Sci Technol Adv Mater. 2020 Mar 19;21(1):195-204. doi: 10.1080/14686996.2020.1736948. eCollection 2020.

Authors

Takafumi Ishibe¹, Yoshiki Maeda¹, Tsukasa Terada¹, Nobuyasu Naruse², Yutaka Mera², Eiichi Kobayashi³, Yoshiaki Nakamura¹

Affiliations

¹ Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan.
² Department of Fundamental Bioscience, Shiga University of Medical Science, Otsu, Shiga, Japan.
³ Kyushu Synchrotron Light Research Center, Tosu, Saga, Japan.

Abstract

For realization of new informative systems, the memristor working like synapse has drawn much attention. We developed isolated high-density Fe₃O₄ nanocrystals on Ge nuclei/Si with uniform and high resistive switching performance using low-temperature growth. The Fe₃O₄ nanocrystals on Ge nuclei had a well-controlled interface (Fe₃O₄/GeO_x/Ge) composed of high-crystallinity Fe₃O₄ and high-quality GeO_x layers. The nanocrystals showed uniform resistive switching characteristics (high switching probability of ~90%) and relatively high Off/On resistance ratio (~58). The high-quality interface enables electric field application to Fe₃O₄ and GeO_x near the interface, which leads to effective positively charged oxygen vacancy movement, resulting in high-performance resistive switching. Furthermore, we successfully observed memory effect in nanocrystals with well-controlled interface. The experimental confirmation of the memory effect existence even in ultrasmall nanocrystals is significant for realizing non-volatile nanocrystal memory leading to neuromorphic devices.

Keywords: 212 Surface and interfaces; Memristor; germanium; interface control; iron oxide; nanocrystal; resistive switching characteristics; silicon.

Grants and funding

This work was supported by a Grant-in-Aid for Scientific Research A Grant No. [16H02078 and 19H00853] and for Exploratory Research [19K22110]; Japan Society for the Promotion of Science.