Effect of gamma irradiation on resistive switching of Al/TiO2/n+Si ReRAM

The Total Ionizing Dose (TID) effects of 60Co gamma ray radiation on the structural and resistive switching behavior of Resistive Random Access Memory (ReRAM), with the device structure of Al/TiO2/n+Si are experimentally investigated. The TiO2 thin films were deposited with Plasma Enhanced Atomic Layer Deposition (PEALD) technique. These devices were gamma irradiated with the dose of 5 kGy to 25 kGy in equal steps of 5 kGy/hr and investigated. The structural changes and surface morphology of these devices were characterized by X-ray diffraction (XRD), Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM). XRD studies revealed that gamma irradiation induces crystalline nature in TiO2 thin films with mixed anatase and rutile phases of TiO2. From FESEM cross sectional results, a deformation in TiO2 film was observed after exposure to 25 kGy. The I-V characteristics of ReRAM devices exhibited a typical bipolar resistive switching in as deposited as well as gamma irradiated devices exposed to dose up to 20 kGy. The devices exposed to 25 kGy dose do not exhibit the resistance switching characteristics. A significant modification between resistive switching behavior of the devices, structural changes in the material, surface morphology and weight % of anatase and rutile phases were observed. This study focuses on the characteristics of TiO2 based ReRAM under radiation environment of 60Co gamma rays of doses in the range of 5 kGy to 25 kGy.