Mechanism for bipolar resistive switching in transition metal oxides based memory cells
María José Sánchez
Centro Atómico Bariloche and Instituto Balseiro, CNEA, (8400) San Carlos de Bariloche, Argentina
DEI - Aula Beta, Ed. 24
6 luglio 2012
Motivated in its potential technological application in post-silicon electronic memory devices, the resistance switching effect in transition metal oxides is attracting a great deal of attention. This effect is a reversible and nonvolatile change in the resistance after the application of electrical (voltage or current) pulses. It has been observed in a plethora of systems, ranging from simple and complex oxides to organic compounds, though each one showing specific characteristics. Here, we focus on complex transition metal oxides (TMO) and introduce a model that qualitatively describes the migration of ionic defects (oxygen vacancies) at the nano-scale TMO-electrode interfaces. Our model shows that in those regions, that are highly resistive and often form Schottky barriers, strong electric fields develop, leading to a spatially inhomogeneous oxygen vacancies distribution and a concomitant resistive switching effect. Our numerical simulations under typical voltage protocols qualitatively reproduce key non-trivial resistance hysteresis experiments that we also report, thus providing valuable support to our model.
Area di ricerca:
Microelettronica e tecnologie emergenti