Study On The Switching Mechanism And Performance Of Graphene Oxide Based Resistive Memory Device

The physical scaling challenges of traditional FLASH memory limits their application for further high-capacity data storage requirement.Overcoming this limitations will require innovations in device structure and device working mechanism.Nonvolatile resistive memory(RRAM)has attracted attention because of its super speed,long retention time,low power cost and simple device structure.The traditional RRAM device is a metal/insulator/metal(M/I/M)this sandwich structure,through the electrical signal to achieve resistance switching.So far in a variety of materials found in the resistance transition effect,including metal oxides,metal sulfide,organic compound,amorphous silicon,carbon,etc.The graphene oxide(GO)material exhibits good application prospects in the field of microelectronics with its unique photoelectric properties.Graphene oxide material have also been reported for their resistive switching memory applications because of simple preparation process,large area film formation,easy to control the electrical properties and other advantages.The research shows that GO has the advantages of flexibility and transparency,which is the next generation of memory material with great potential.However,switching mechanism is not clear,the device performance is poor,which will limit the development of GO RRAM.This paper will start from the discussion of conductivity mechanism of GO-based memory and the improvement of device resistance performance.Specific research is as follows:On the study of switching mechanism:The Al/GO/Al devices,Au/GO/Au devices was fabricated using electrodes having different oxygen activity,and investigated the resistance behavior of graphene oxide-based resistive memory.Through the characterization of the electrical characteristics of the device and the study of the electron conduction mechanism,it is confirmed that the resistivity mechanism is the conversion of sp2 and sp3states.Finally,the Au/GO/Au device with planar structure is fabricated by UV lithography.The mechanism of GO resistance was further analyzed by analyzing the changes of material structure during the process of GO switching resistive in situ and the analysis of the change of the composition before and after switching resistive of GO material by XPS energy spectrum and Raman spectroscopy.On the study of performance improvement method:In this paper,the localized electric field is used to control the internal oxygen distribution of the material by using TiO2 nanoparticle doping and ultraviolet light irradiation to optimize the device's resistance performance for the problems such as the fluctuation of the device parameters and the large operation voltage caused by the randomness of the formation and disconnection of the GO RRAM conductive channel.The results show that the local electric field can reduce therandomness of the conductive channel,effectively improve the device resistance stability,in addition,the device power is also effectively reduced.The method is a simple and practical means of optimizing the stability of GO resistance memory.