Characterizations Of Resistive Switching Behavior Of BaTiO₃/CoFeB/BaTiO₃ Trilayer Films

With the development of the whole society, more and more information surround us every day, and the amount of information that needs to reserve, of course, becomes larger and larger with it. The storage of information can not be achieved without memories. In current days, the most frequently used memory is Flash memory, which is a non-volatile random access memory. Compared with the original volatile random access memory, Flash possesses many advantages, and this provides us great convenience. Almost all of the memory that our mobile phones and computers used now is Flash. As people’s requirement for information storage becomes higher and higher,the size of single memory cell is descending, Flash is facing with mounting challenges posed by the limitations of manufacturing technique and theoretical basis, because when the size of single memory cell reduces to the quantum size, the storage of information will be strongly affected by the quantum size effect and becomes unstable. At this circumstance, we need to find out a new random access memory to replace the flash,this new memory must be non-volatile, moreover, it should possesses advantages such as high storage density, high read/write speed, low power consumption and low cost,only this, it has the chance to becomes the next-generation non-volatile memory.Nowadays, among the Flash’s successor including Magnetoresistance Random Access Memory, Ferroelectric Random Access Memory, Phase Change Random Access Memory and Resistive Random Access Memory, researchers holding out the greatest hope for the Resistive Random Access Memory, deem it as the most potential candidate for the next-generation non-volatile memory. Resistive Random Access Memory is anew type of random access memory, it is based on the resistive switching effect—one of the hot research areas in physics — which means the resistance of materials can be reversibly switched by the electric field. Based on this foundation, we study the resistive switching behavior of BaTiO₃/Co FeB/BaTiO₃ trilayer films, main content is as follow:（1）Simply introduced the fundamental properties of Co FeB alloy and BaTiO₃ which is a common perovskite oxide, and analyze the mechanism and advantages of several new type of random access memory device.（2）Explain the resistive switching effect including its category, current conduction mechanisms and physical mechanisms in details.（3）Introduced several prepared methods of thin films including Molecular Beam Epitaxy, Pulse Laser Deposition, Sol-Gel, Hydrothermal synthesis and Magnetron sputtering, and introduced several characterization technique of thin films and the basic mechanism of the instruments that used for the characterization..（4）Simply narrate the main experimental process, and show characterization results of few important parameters of the thin films after the sample’s preparation is finished.（5）Introduced the measuring results of the resistive switching effect in details,analyze the effect of external conditions on the resistive switching, at last, we made a reasonable explanation for the resistive switching effect of the samples.Results indicate that the BaTiO₃/Co FeB/BaTiO₃ trilayer films we prepared possess only a weak resistive switching effect, but the resistive switching effect can be greatly enhanced by the light irradiation. The Set voltage decreased with the increase of the irradiation intensity, whereas the ratio of high resistance to the low resistance increased with the increase of irradiation intensity. The resistive switching effect of the sample show a good stability, under light irradiation, the I-V curves have no obvious decay in70 integrated cycles. The fitting results of I-V curves show that the current conduction mechanism of low resistance state follows the Poole-Frenkel emission mechanism,whereas the conduction mechanism of high resistance state follows Space charge limited current mechanism. Analyses indicate that the resistive switching of the sample originate from the trapping and detrapping of electrons near the interface of CoFeB and bottom BaTiO₃, and the enhancement of the resistive switching under light exposure is attributed to the photoelectrons generated by the light irradiation.