The Tunable Resistive Switching Behaviors In NiO-based Composite Films

With the development of large scale integrated circuits technology, the device shows a powerful processing capability. Now, the Si-based Flash has shown a great performance. Meanwhile, there is continued demand of high-speed,high-density, low-power memory, making the next generation of storage research and development is around the corner, and resistive random access memory was high hopes. In this paper, the polycrystalline Ni O,doped Ni O and composite Zn O/ Ni O films were prepared by the sol-gel method on the ITO substrate. And the Al electrode was prepared by the vacuum thermal evaporation method. By control the compliance current(CC), doping elements, doping concentration and composite of Zn O, the different resistive switching behaviors and conduction mechanisms were explored. It will help for the application of binary resistive oxides and provide data and theory support. The details of experiments and main results are summarized as follows:(1) By control forming and switching CC, an abnormal coexistence of URS,BRS, and TRS was found in the same Al/Ni O/ITO device. With the help of the fitting curves and XPS test, a dual-oxygen reservoir structure in which the ITO and Al Ox-Ni Ox interface acts as the oxygen reservoirs and Joule heating model were presented. Finally, the reset process of both URS and BRS were interpreted by the filament rupture process under the Joule heating effect. The study of this abnormal behavior will help people to more clearly understanding of the resistive behavior, at the same time by reasonable regulation that could effectively avoid the volatile resistive switching behavior.(2) The Al/Li:Ni O/ITO device at low doping concentration shows good reproducibility and high ON/OFF ratio nonlinear BRS. By the XPS test, a higher concentration of oxygen vacancies was found in the Li:Ni O film. Combined with dual-oxygen reservoir structure, the electronic transitions can be explained by co-effects of the interface and inner defects. The nonlinear BRS will help to resolve the sneak currents in the device.(3) For the I-V curves of the Mn:Ni O device, the transmittance was decreased with the concentration of Mn-doped devices increases. Meanwhile, itintroduce of more doping impurity level, so the band gap becomes smaller. But the set and reset voltage was decreased which can help to reduce the power consumption of the device.(4) Coexistence of bipolar resistive switching behaviors with linear and nonlinear characteristics is demonstrated in an Al/n-Zn O/p-Ni O/ITO device.From the I-V and fitting curves, after analyzing the structure of the device, the linear behavior is dominated by conductive filaments model, while the nonlinear switching obeys the co-effects of the Al Ox interface and p-n junction. For a study of the endurance, the nonlinear behavior of the n-Zn O/p-Ni O device is superior to Li doped Ni O.The results implied that many kinds of resistive switching behaviors were coexistence in an Al/Ni O/ITO structure. By the control the compliance current, a tunable resistive was shown in the I-V curve. Secondly, Li-doped Ni O could enhance the stability and repeatability of nonlinear resistive bipolar. Finally, a superior nonlinear bipolar resistive was obtained in the Zn O/Ni O composite film.It not only can reduce the power consumption of the device, but also help solve the problem of sneak current. It also has a great value for the application of RRAM.