Resistive switching characteristics of directly patterned Y-doped CeO₂ by photochemical organic-metal deposition

Resistive RAM (ReRAM), which uses the anion-based resistive switching characteristic of transition metal oxide, is one of the strong candidates for next-generation non-volatile memory. The resistance switching characteristics depend on oxygen defects and their electrochemical migration. This study systematically investigated the Y³⁺ doping effect in CeO₂ resistive switching behavior to control oxygen vacancy. The resistive switching devices of Ce_1-xY_xO_2-y (CYO) (x = 0, 0.05, 0.1, 0.15, and 0.2) were fabricated by the photochemical metal-organic deposition method, which could successfully obtain directly patterned CYO films. The XRD pattern and Raman spectrum confirmed that the lattice shrink and structural distortion was induced and increased gradually by increasing the oxygen vacancy concentration with yttrium content. All the CYO devices showed bipolar filament-type resistive switching, and both resistance of the pristine state and forming voltage decreased with increasing Y content from an increase in oxygen vacancy concentration. And the on/off ratio decreased with increasing Y content because of reduced HRS resistance, even after the recovered insulation oxide region by HRS switching, due to fixed defect sites with trapped electrons formed by yttrium. And with a SPEM experiment, we found that ceria loses 24% oxygen for LRS resistive switching, which induced a resistance change of about five orders of magnitude.