When scaling the lateral size of a ferroelectric random access memory (FeRAM) device down to the nanometer range, the polarization switching-induced displacement current becomes small and challenging to detect, which greatly limits the storage density of FeRAM. Here, we report the observation of significantly enhanced injection currents, much larger than typical switching currents, induced by polarization switching in BiFeO3 thin films via conductive atomic force microscopy. Interestingly, this injected current can be effectively modulated by applying mechanical force. As the loading force increases from ∼50 to ∼750 nN, the magnitude of the injected current increases and the critical voltage to trigger the current injection decreases. Notably, changing the loading force by an order of magnitude increases the peak current by 2-3 orders of magnitude. The mechanically boosted injected current could be useful for the development of high-density FeRAM devices. The mechanical modulation of the injected current may be attributed to the mechanical force-induced changes in the barrier height and interfacial layer width.
Bibliographical noteFunding Information:
This publication has emanated from research supported by the China Scholarship Council, the National Natural Science Foundation of China (U1932125, U1832104, and 92066203), the Foundation for Basic and Applied Basic Research of Guangdong Province (2020A1515010996), the Project for Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2018, the Guangdong Science and Technology Project-International Cooperation (Grant No. 2019A050510036), the Engineering and Physical Sciences Research Council through contract EP/S037179/1, the Department for Economy-NI through the U.S.–Ireland Research and Development Partnership Programme USI-082, and Science Foundation Ireland (SFI) under the U.S.–Ireland R&D Partnership Programme (SFI/14/US/I3113) and the Career Development Award (SFI/17/CDA/4637).
Copyright 2021 Elsevier B.V., All rights reserved.
- injected current
- mechanical force
ASJC Scopus subject areas
- Materials Science(all)