Conduction mechanism of resistive switching films in MgO memory devices

摘要

In this work, nonpolar resistance switching behavior was demonstrated in Pt/MgO/Pt structure. The resistance ratio of high resistance state (HRS) and low resistance state (LRS) is about on the order of 10~5 for the compliance current (I_(comp)) of 1 mA at 300 K. Using enough I_(comp) (≥0.5 mA) during SET processes, the LRS resistances reach a minimum of about 10~2- 10~3 Ω and the RESET currents reach a maximum of about 10~(-4)-10~(-3) A. Experimental results indicate that the conduction mechanism in MgO films is dominated by the hopping conduction and the Ohmic conduction in HRS and LRS, respectively. Therefore, the electrical parameters of trap energy level, trap spacing, Fermi level, electron mobility, and effective density of states in conduction band in MgO films were obtained.