Memristive and structural properties of metal oxides obtained via electroplating

As one of the most promising memory devices, memristor has the advantages of high-density data storage, low power consumption, faster operation and non-volatility over the conventional architectures. Having the potential usage in not only memory applications but also bio-mimicking systems, chaotic circuits and neural systems, memristive systems draw attention in the electronics industry. Despite its advantages, difficulties on understanding and controlling the conduction mechanism prevent the widespread use of memristive systems. Most basic parameters that affect the behavior of the memristor are fabrication conditions and materials used for electrodes and active layer. In the thesis study, active layer fabrication is realized with electrochemical deposition which is easy to control and cost-effective method. Aqueous methanesulfonic acid (CH3SO3H) solution is used to perform anodic oxidation of Ti to produce an oxygen-deficient TiOx layer with certain stoichiometries. Metal ion introducing to the active layer is known to improve the switching performance of memristor. Therefore, addition of Mn+2 at different concentrations to the main solution is performed and the impacts on the anodization mechanism and conductivity of the TiOx layer are discussed. Additionally, effects of electrochemically active and passive materials as electrodes are examined in terms of conduction mechanism and device performance. Characterization of the thin film is carried out using different metrology techniques. AFM and SEM analyses are performed to reveal surface topography. XRD results show that the oxygen deficient Magneli phase TiOx formation is achieved without the additional procedures such as annealing. According to the EDX and XPS, Mn+2 is joined the oxide structure as MnOx. Also, thin film thickness measurements indicate that the additive Mn+2 ions promote the formation of thicker oxide layer. Depending on the manganese concentration, bipolar or interface type switching mechanisms are observed. Consequently, the relation between the thickness of the structures, oxygen content, manganese concentration and electrical properties is examined.