The Preparation Of TiO₂ Nanotube Array Films And Their Resistive Switching Characteristics

This article first briefly introduces the concept and storage mechanism of various new types of non-volatile memory,and summarizes the theoretical basis and material system,research status and problems of the memristor as a new generation of non-volatile resistive memory.Then it focuses on the research works done by the author on the topic of"The preparation of TiO₂ Nanotube Array Films and their resistive switching characteristics"during the studying of master's degree.In this paper,the TiO₂ nanotube arrays film?TNAs?is selected as the resistive switching dielectric layer material.A series of Ti/TNAs/Al memristor samples were designed and assembled,to investigate the effect of different anodization time and different reduction conditions on the resistive switching properties of Ti/TNAs/Al structure.The main research work includes the following two aspects:1)A Ti/TNAs/Al resistive switching devices was prepared by anodization and evaporation methods.The resistive properties of five samples with TNAs dielectric layer oxidation time of 10,20,30,60 and 90 min were compared and studied.The results show that the 90,60,30 min samples have typical analog resistive switching behavior,while the oxidation time is 20 and 10 min,the samplespresent the digital resistive switching behavior.The analysis shows thatthe analog and digital resistive mechanisms are dominated by the electronstrapping/detrapping processrelated by oxygen vacancies trap and the formation/breaking mechanism of the oxygen vacancy conduction paths under an external electric field.2)On the basis of the above works,a sample of Al/TNAs/Ti memristor treated by different cathode reduction voltages was designed and prepared.It try to improve the HRS/LRS ratio of the digital resistive behavior of the sample by introduce oxygen vacancies into the sample by cathode reduction.The experimental results show that when the reduction voltage is increased to 5,10,15 and 20 V,the device exhibits a significant digital resistive switching behavior,and the switching ratio is gradually increased,reaching a maximum of 10⁶.It confirmedthe expectation that the new experimental methodof cathodic reduction can improve the HRS/LRS ratioof sample,and the effect is satisfactory.