A simplified method to determine carrier transport mechanisms of metal-oxide resistive random access memory (RRAM) devices

Abstract

The current carrier transport mechanism in non-linear resistance states of the current–voltage (I–V) curves of the resistance changing or resistive switching (RS) based random access memory (RRAM) devices would help to understand the physics behind the resistive switching phenomena. The non-linear portion of the I–V curves are most commonly categorized by three different types of conduction mechanisms, the space charge limit current (SCLC), the Schottky emission (SE) and the Poole-Frenkel (P-F) effect respectively. In this study, the current–voltage curves of the RS devices limited to the non-linear region were plotted on a log–log scale with the purpose of distinguishing the dominant current conduction mechanisms. Each of the I–V curves narrowed to the non-linear region were re-plotted for SCLC at the scale of I vs. V2, for SE at the scale of ln I vs. √V and for P-F at the scale of ln I/V vs. √V. The linear fitting lines were plotted and calculated for each one using linear fitting techniques. The slopes of the fitting lines were found respect to the scales using linear fitting equations. The conduction mechanisms of the devices were determined numerically using the degree of linearity of the slopes. Finally, the offered method was applied to TiO2 based resistive switching device.