Interfacial layer assisted, forming free, and reliable bipolar resistive switching in solution processed BiFeO3 thin films

Chandni Kumari,Shree Prakash Tiwari,Ambesh Dixit,Ishan Varun

doi:10.1063/1.5134972

Chandni Kumari, Shree Prakash Tiwari + Show 2 more

Open Access

https://doi.org/10.1063/1.5134972

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Journal: AIP Advances	Publication Date: Feb 1, 2020
Citations: 26	License type: cc-by

Affiliation: Indian Institute of Technology Jodhpur

Abstract

BiFeO3 based resistive random access memory (RRAM) devices are fabricated using a low-cost solution process to study the effect of an Al top electrode on switching behavior and reliability. Fabricated devices demonstrated bipolar switching characteristics with a moderate Ion/Ioff ratio, set and reset voltages of ∼−1.3 V and ∼0.8 V, DC and AC endurance of more than 250 cycles and 7100 cycles, respectively, and a retention time of over 104 s, confirming the non-volatile resistive switching behavior. The ohmic and trap filled space charge limited conduction dominates the conduction mechanism in the devices at lower and higher voltages, respectively. Moreover, impedance spectroscopy measurements substantiate the presence of an AlOx layer at the Al/BiFeO3 interface resulting from the Al–O interaction at the junction, which is the possible rationale of reliable complementary switching in these RRAM devices. The switching mechanism is elucidated using the formation and rupture of the oxygen vacancy mediated filament, assisted by the participation of a thin AlOx layer at the Al/BFO interface. The role of the thin AlOx layer is explained by modeling of impedances.

Highlights

Memory devices are the crucial elements of electronic systems and have been previously developed as drum memories, capacitor memory, magnetic core memory, matrix core memory, magnetic cards/tapes, and flash memory.[1,2] As per the demand of the current electronic industry, non-volatile memory devices should possess characteristics such as being fast and scalable, a large retention time, and low power consumption together with low material and processing costs.[3]
The limitations of scaling and slow speed in commonly used flash memory devices encouraged the development of fast and reliable memory devices, such as the magnetic RAM (MRAM),[4,5] phase change RAM (PCRAM),[6,7] ferroelectric RAM (FeRAM),[8,9] and resistive RAM (RRAM), which are being explored as probable alternatives to the existing flash memories.[1]
The RRAM devices are composed of a facile metal–insulator–metal (MIM) architecture, where the data have been stored in multiple electrical resistance states, namely, low resistance states (LRSs) and high resistance states (HRSs)

Summary

Introduction

Memory devices are the crucial elements of electronic systems and have been previously developed as drum memories, capacitor memory, magnetic core memory, matrix core memory, magnetic cards/tapes, and flash memory.[1,2] As per the demand of the current electronic industry, non-volatile memory devices should possess characteristics such as being fast and scalable, a large retention time, and low power consumption together with low material and processing costs.[3]. These polarity dependent set and reset processes substantiate bipolar resistive switching in Al/BFO/FTO RRAM devices.

Results

Conclusion