Tuning the resistive switching characteristics of BiFeO3 by Ar+ irradiation (Best Poster Award)

Sufficient and stable read current is critical for the scalability of RRAM devices and designing of multilevel resistive switching devices.
Here, we report that a remarkable increase of the current density and retention stability of Au/BiFeO3/Pt/Ti resistance random access memory (RRAM) devices can be achieved by low-energy (≤ 1 keV) Ar+ ion irradiation of BiFeO3 films.
According to dynamic simulations and microstructure characterizations, oxygen atoms are preferentially sputtered from the BiFeO3 surface by Ar+ ion irradiation. The generation of oxygen vacancies acting as "dopants" modifies the Schottky contact of the Au/BiFeO3 interface and also may contribute to the formation of highly conductive "shunt" channels. These two effects are proposed as the reasons for the increased current density by more than two orders of magnitude and the improved retention stability. After Ar+ irradiation the retention stability was increased as the current density remaining after the retention time is improved from 7% to 85% of the initial value.