Deposition Atmosphere Dependency of Nonvolatile Resistance Change Phenomenon in GZO-ReRAM

Flexible transparent Resistive Random Access Memory (FT-ReRAM) consisting of Ga-doped ZnO (GZO) film not only as a memory layer but also as electrodes on the large PEN sheet were fabricated. The dependence of memory effect on the atmosphere during the memory layer sputtering was investigated. Resistive switching effect of the memory layer was investigated by directly applying voltage using conducting-AFM. Both memory layers deposited in H2 atmosphere, GZO(H2), and that in O2 atmosphere, GZO(O2), showed bipolar resistive switching with the same bias polarity dependence. I-V measurement for GZO(H2) showed that the relationship between applied bias polarity and consequent resistive change was the same as the result of C-AFM measurement. However, in GZO(O2), the bias polarity dependence observed in I-V measurement was opposite to that observed in C-AFM measurement. This result suggests that the atmosphere during the memory layer deposition affects the bias polarity dependence of bipolar resistive switching even in the ReRAM which has symmetrical structure.