Characterization of gadolinium oxide thin films with CF4 plasma treatment for resistive switching memory applications

摘要

The effect of the CF_4 plasma treatment on the gadolinium oxide (Gd_xO_y) thin films for the resistive random access memory (RRAM) applications was investigated. The material properties of the fluorine incorporated Gd_xO_y films were analyzed by the X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS) and ultraviolet-visible spectroscopy (UV-VIS). Further, the set and reset voltages of the Pt/Gd_xO_y/W RRAM devices with the CF_4 plasma treatment were effectively reduced to -1.15 and 2.1 V respectively owing to the low Schottky barrier height. The formation of Gd-F bonds can prevent the oxygen atoms from out-diffusing through Pt grain boundaries into the atmosphere, leading to the superior retention characteristics for over 10~4 s. The CF_4 plasma treated Gd_xO_y RRAMs can sustain a resistance ratio of 10~2 for more than 800 times stable set/reset cycling, suitable for future low-voltage and high-performance nonvolatile memory operation.