ABSTRACT
Resistance switching, which refers to the alternating of the conductance triggered by the external electrical field, is a very fundamental physical phenomenon of dielectrics. Resistive switching observations in a wide range of materials were reported subsequently. Majority of them were noncrystalline phase metal oxide–based systems. In 1970, one of the most important reviews on resistive switching was given by Dearnaley, where the concept of resistance random access memory (RRAM) was well established. Resistive switching and RRAM have been reviewed frequently thanks to the fast progress in technology development and underlying mechanisms investigation. Based on IRTS 2010 update, RRAM was considered to be one of the emerging memory devices along with nanomechanical memory, polymer memory, and molecular memory due to the long duration of technology development and polishing. A very critical piece of evidence on the transport type of RRAM comes from conductance as a function of frequency.
