Methods of controlling operation modes in Pt/TaO x /Ta2O5/Pt resistive switching cells

Abstract

Abstract Forming and resistive switching (RS) characteristics of Pt/TaO x /Ta2O5/Pt cells were investigated when the TaO x thickness was varied. With an increase in the TaO x thickness, a semi-forming process, which is defined as a transition from an initial state to high resistance states more than 1 kΩ, occurs more frequently. The semi-forming can be understood as the formation of an incomplete filament with a gap or a constricted part in the Ta2O5 layer. Moreover, in a single cell after the semi-forming, selective control of RS operation modes was achieved by simply adjusting the range of the applied voltage. In a complementary RS mode where both set and subsequent reset processes occur at both positive and negative voltages, analog RS characteristics can be observed. The control of the RS operation modes could be useful for the improvement of the multi-leveled controllability of resistance.