The Resistance Switching Characteristics Study For Silicon Tungsten Oxygen Film Deposited By HWCVD

At present,in the field of non-volatile memory(NVM),Flash memory used widely is difficult to meet the requirements of the memory in the current large data age because of many factors such as reading and writing speed,working life,working voltage and so on.Therefore,it is urgent to develop new non-volatile memory.Among a variety of new non-volatile memories,the resistive switching memory which based on resistance change modulated by electrical stimulus,has inspiring the research upsurge of scientific research personnel due to its excellent area compaction,high switching speed,high endurance,good retention and low power consumption.In this paper,firstly the development prospect of four new nonvolatile memory is compared,and the technical advantage of the resistive memory is clarified.Secondly,the technology of deposited silicon tungsten oxide thin film by hot filament chemical vapor deposition(HWCVD)method is deeply studied.Then the effect of the growth rate and refractive index of the film on substrate temperature is analyzed.It is found that the deposition rate of the film increases with the increase of the substrate temperature,which is related to the surface process of the film growth,and the high deposition rate lead to declining the refractive index of the film.The composition and morphology of the films were characterized by FTIR,XPS and SEM later.The FTIR show that the content of C impurities in the film decreases with the increase of the substrate temperature and the content of C and H impurities in the film is reduced after annealing;XPS show that the relative proportion of W,Si and O elements in the thin films is 20.40%,13.13%and 66.44%respectively,and O(combined W)/W=1.9,O(combined Si)/Si=2.1 and SEM show that the film is characterized by a compact structure,smooth surface.It meets the needs of preparing RRAM devices.Finally,a resistive memory based on Ag/Si _XW_YO_Z/Si structure is fabricated.The I-V test results show that the Ag/Si _XW_YO_Z/Si structure exhibits bipolar switching behavior,and the forming voltage of the device is 6V and the setting voltage is 3.2V.When different limiting current is applied,the resistance of the device at low resistance state decreases with the increase of the limiting current.The breaking current of the device at high resistance state will increase with the increase of the limiting current.Moreover,the device with smaller electrode size shows a higher ratio of high and low resistance.The I-V curve fitting proves that the resistive behavior of the RRAM device with Ag/Si _XW_YO_Z/Si structure is achieved by the formation and fracture of the conductive filaments.