Capacitive and RRAM Forming-Free Memory Behavior of Electron-Beam Deposited Ta2O5 Thin Film for Nonvolatile Memory Application

Thepresent study reports the presence of capacitive memory andforming-free resistive random access memory (RRAM) in a tantalum pentoxide(Ta2O5) thin film (TF) device. The capacitanceand voltage analysis of the electron-beam evaporated Ta2O5 TF device exhibits three distinct regimes: inversion,depletion, and accumulation, which decrease as the frequency of operationincreases. This behavior is attributed to the interface state density(D (it)) and series resistance (R (s)). Moreover, the memory window of the Ta2O5 device was found to increase from 1.2 (+/- 1 V) to 7.9(+/- 10 V). Furthermore, the resistive switching mechanism wasinvestigated through the current (I) vs voltage (V) measurement for 1000 cycles. The device exhibits abnormalforming-free bipolar resistive switching. In addition, a desirableand stable switching behavior with resistance ratio of 10(2) and a retention up to 10(3) s at +2.5 V was observed. Theoverall findings of the Au/Ta2O5 TF/Si devicecould provide a pave way for nonvolatile memory (NVM) application.