Research On The Resistance Switching Characteristics In BiFeO₃ Thin Films

With the advancement of science and technology,the demand for human life,and the rapid spread of portable electronic devices,people are increasingly demanding the miniaturization and high performance of devices.Because of simple structure,large capacity,high stability and low cost,non-volatile memory has been widely used in the rapidly developing digital intelligent world.The current market demand for non-volatile memory is getting larger.The recent development of non-volatile memory technology is very encouraging,and there are many new technologies to be choosed.However,current non-volatile memory devices still have limitations that limit their use as auxiliary storage devices.Therefore,people are highly expected to have denser,faster,and lower-energy nonvolatile memories.So,nanostructures have become the key.Resistive memory has the advantages of simple structure,high storage density,fast read and write speed,long data storage time,etc.It has become an important candidate for developing new non-volatile resistive random access memory.Resistive switching effects have been observed in various transition metal oxides and complex perovskite oxides,but the proper description of the resistive switching drive mechanism is still an important issue in the development of resistive random access memories.Therefore,further research is very important to clearly explain the phenomenon of resistance switching.With the continuous expansion of data storage and sensor application requirements,materials with excellent ferroelectricity and piezoelectricity have received great attention.BiFeO₃ has attracted much attention due to its excellent performance in epitaxial and polycrystalline films.It may be the only material that has magnetic and ferroelectric properties at room temperature.Therefore,its effect on the polycrystalline field Comparable to the copper oxides in superconductors.And there have been hundreds of publications devoted to it in the past few years.In addition,because BiFeO₃ has a high Curie temperature,it also has a good prospect in high temperature applications.This paper describes the structure,basic physical properties and device applications of BiFeO₃ in detail.Based on this,the resistance switching characteristics of BiFeO₃ multilayer films were studied.The preparation process of the samples,the characterization of the samples,the measurement of the resistance switching characteristics of the samples and the analysis of the results were described in detail.Some notes and parameters settings in these processes were briefly described.The specific content is as follows:?1?BiFeO₃/C/Ag thin films were prepared by magnetron sputtering,and the cross-sections of the samples were characterized by scanning electron microscopy?SEM?.Then the resistance of the multilayer film was tested with Keithley 2400.The multilayer film has been tested and found to have typical resistance switching characteristics.Subsequently,the effect of annealing temperature on the resistive switching characteristics of BiFeO₃/C/Ag thin films was studied.The experimental results demonstrate that the current of the sample increases with the annealing temperature,and as the annealing temperature increases,the resistance switching characteristics of the sample become more and more obvious.,and made a tentative explanation of this phenomenon.?2?ZnO/BiFeO₃/ZnO films were prepared by magnetron sputtering equipment.The cross-sections of the samples were characterized by SEM.Then,the resistance of ZnO/BiFeO₃/ZnO thin films was tested,and the influence of light on the resistive switching characteristics of ZnO/BiFeO₃/ZnO thin films was studied.From the experimental results,it can be concluded that the resistance switching behavior of the sample becomes obvious under light conditions,and the sample has an asymmetrical resistance switching characteristic.This may be due to the random and non-uniform trap distribution in the ZnO/BiFeO₃/ZnO memory cell and the asymmetric barrier between the Ag/ZnO interface and the ZnO/Si interface.Finally,the stability of the resistive switching characteristics of ZnO/BiFeO₃/ZnO thin films was evaluated.The results show that the resistive switching characteristics of this sample are highly repeatable.