Resistive switching properties of films deposited by cathodic arc

MÁRQUEZ, ADRIANA; ACHA, CARLOS; KLEIMAN, ARIEL

Foz do Iguazu

Encuentro; XX Encontro da Sociedade Brasileira de Pesquisa em Materiais (SBPMat-2022); 2022

SBPMat

Cathodic arc deposition (CAD) has demonstrated to be an efficient method for the deposition of transition metal thin films. A cathodic arc is a low voltage, high current discharge between two electrodes in a vacuum chamber in which the cathode material is vaporized. The plasma forms by ionized vapor phase species provide the base elements for the thin film. Films of compounds can be obtained by introducing a reactive gas into the chamber, which chemically reacts with the vapor phase species. Together with the plasma, some macroparticles (MPs) are emitted from the cathode. MPs produce protuberances and depressions on the film surface, which deteriorate some properties of the coatings. Different filter designs have been developed to separate the MPs from the ion flux. In general terms, magnetic filters avoid a direct line of sight between the cathode and the substrate and guide the plasma flux to the substrate by means of electromagnetic fields. The structure of the deposited films can be controlled through different deposition parameters, such as the substrate bias and the temperature employed during the process.Recently, the use of films in a metal-insulator-metal device configuration, where one of the metal layer is a transition metal, the insulator is a transition metal oxide and the third layer is a metal contact of Au or Pt, has been evaluated as a better alternative for the development of resistive non-volatile memories (Re-RAM). The performance of the Re-RAM is based on the resistive switching (RS) mechanism, directly involving the insulator or the interfacial zones close to the two-terminal electrodes [1]. Low and high resistive states can be programmed by application of voltage pulses to the metal electrodes. TiO2 films on a Ti layer deposited by CAD with MP filter were studied toward their use in Re-RAM devices. These films, in combination with a sputtered Pt top layer, were tested as capacitive-type resistive memories. The resistive switching was evaluated by applying current–voltage cycles (I-V). Our results indicate that the properties of RS can be tuned according to the crystalline structure of TiO2, favoring or not the stability of resistive hysteresis loops and even modifying which of the oxide-metal interfaces is the most active in the writing-erasing processes.