Resistive Switching Characteristics of Si-Rich Oxides with Embedding Ti Nanodots

We have studied a formation of Ti nanodots (NDs) by remote-H2 plasma (H2-RP) treatment and an impact of Ti-NDs embedding into Si-rich oxide (SiOx) on the resistive switching behaviors because it is expected that NDs can trigger the formation of the conductive filament path in SiOx. Atomic force microscope (AFM) analysis shows that a combination of a Ge(~20 nm)/Ti(~3 nm) stacked layer with subsequent H2-RP exposure is effective to form the high-density Ti-NDs, where Ge layer is used as a barrier layer against oxidation of the ultrathin Ti layer. From X-ray photoelectron spectroscopy (XPS) analysis, an etching of Ge layer by H2-RP exposure and surface oxidation of Ti-NDs by air exposure are observed. After fabrication of SiOx-ReRAMs with the NDs, resistive switching characteristics are measured from current-voltage (I-V) curves and compared to the results obtained from the diodes without the NDs.