Capacitive and RRAM Forming-Free Memory Behavior of Electron-Beam Deposited Ta<sub>2</sub>O<sub>5</sub> Thin Film for Nonvolatile Memory Application
Elangbam Rameshwar Singh, Mir Waqas Alam, Naorem Khelchand Singh
Abstract
The present study reports the presence of capacitive memory and forming-free resistive random access memory (RRAM) in a tantalum pentoxide (Ta 2 O 5 ) thin film (TF) device. The capacitance and voltage analysis of the electron-beam evaporated Ta 2 O 5 TF device exhibits three distinct regimes: inversion, depletion, and accumulation, which decrease as the frequency of operation increases. This behavior is attributed to the interface state density ( D it ) and series resistance ( R s ). Moreover, the memory window of the Ta 2 O 5 device was found to increase from 1.2 (± 1 V) to 7.9 (± 10 V). Furthermore, the resistive switching mechanism was investigated through the current ( I ) vs voltage ( V ) measurement for 1000 cycles. The device exhibits abnormal forming-free bipolar resistive switching. In addition, a desirable and stable switching behavior with resistance ratio of 10 2 and a retention up to 10 3 s at +2.5 V was observed. The overall findings of the Au/Ta 2 O 5 TF/Si device could provide a pave way for nonvolatile memory (NVM) application.