Estudio de la influencia de la temperatura sobre los mecanismos de conmutación resistiva en estructuras RRAM de óxido de Hafnio

Debido a la necesidad de nuevas tecnologías en el ámbito de la computación, el almacenamiento de datos o el desarrollo de inteligencias artificiales, los memristores se han postulado como uno de los dispositivos de mayor relevancia en el futuro, ya que comparten una combinación de características muy útiles para estas aplicaciones, como son la gran similitud que poseen con las sinapsis neuronales y la gran utilidad del mecanismo de funcionamiento que poseen. En primer lugar, haremos una descripción de como funciona el resistive switching, los materiales utilizados y los mecanismos que provocan el switching. En este documento nos centraremos en el estudio de un dispositivo TiN=T i=10nm - HfO2=W y la dependencia de sus características con la temperatura durante el resistive switching. En último lugar haremos una breve review sobre las posibles aplicaciones de este tipo de memristores.Owing to the need of new technologies in the field of computing, the storage data or the artificial intelligences development, memristors have been regarded as one of the most relevant devices in the future. Memristors show some useful characteristics for the aforementioned uses. Some of this characteristics are: the similarity with neuronal synapses and the usefulness of the particular mechanism (resistive switching) they show. On first place, we'll make a description of the process of resistive switching, materials used and mechanisms behind resistive switching. Later, we'll focus on the study of dependence of the characteristics in a TiN=T i=10nm - HfO2=W cell with temperature on I-V cycles. Finally we`ll make a short review about the aplications of memristors.Departamento de Electricidad y ElectrónicaGrado en Físic

Influences of the temperature on the electrical properties of HfO2-based resistive switching devices

Producción CientíficaIn the attempt to understand the behavior of HfO2-based resistive switching devices at low temperatures, TiN/Ti/HfO2/W metal–insulator–metal devices were fabricated; the atomic layer deposition technique was used to grow the high-k layer. After performing an electroforming process at room temperature, the device was cooled in a cryostat to carry out 100 current–voltage cycles at several temperatures ranging from the “liquid nitrogen temperature” to 350 K. The measurements showed a semiconducting behavior in high and low resistance states. In the low resistance state, a hopping conduction mechanism was obtained. The set and reset voltages increased when temperature decreased because the thermal energies for oxygen vacancies and ions were reduced. However, the temperature did not influence the power absorbed in the reset transition, indicating the local temperature in the filament controls the transition. The set transition turned from gradual to abrupt when decreasing the temperature, due to a positive feedback between the current increase and the Joule heating at low temperatures.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (Projects TEC2017-84321-C4-2-R and TEC2017-84321-C4-1-R