| Over the past decades, with the growing demand for portable electronic devices, a non-volatile memory has been extensively studied. The conventional non-volatile memories,represented by flash memories, face many technical challenges and some physical limitations,such as high programming voltages, low endurance, low write speeds, and the tunneling oxide scaling limit and other issues. In order to overcome these problems, a variety of new non-volatile memory has emerged. One of them is a resistive random access memory(RRAM),because of its simple structure, high speed, low power consumption, long retention time, has attracted wide attention.In this paper, mainly in the following aspects:The hydrogenated nanocrystalline silicon(nc-Si:H) film were deposited on Pt substrates by radio frequency plasma enhanced chemical vapor deposition technology(RF-PECVD),and device of Ag/nc-Si:H/Pt structure were prepared. The microstructures of nc-Si:H were investigated by X-ray diffraction(XRD), Raman spectroscopy, Fourier transform infrared spectroscopy(FT-IR), and high resolution transmission electron microscope(HRTEM), the results showed that there are nanocrystals embedded in amorphous matrix. The I-V curve of device were tested, the resistive memory characteristics and mechanism of nc-Si:H thin film were discussed. It exhibits a stable three resistance states. The temperature dependence of high resistance state(HRS) and intermediate resistance state(IRS) both show semiconductor behavior, but the low resistance state(LRS) temperature dependence represents metallic property. The fitting of I-V curve demonstrated that the conduction mechanism of HRS, IRS and LRS showed space charge limited conduction(SCLC), tunneling and ohmic characteristics, respectively. We supposed that the discrete Ag filament with Si nanocrystalline and complete Ag filament is proposed to be responsible for the performance IRS and LRS. Si nanocrystalline between discrete Ag nanoparticles contribute to the current transport at IRS.The resistive switching memory device with Ag/BFO/Pt structures were fabricated byRF magnetron sputtering technology, using BFO film as dielectric layer, the switching characteristics of the device under low compliance current were discussed. The results showed that, with the compliance current as low as 0.5μA, the Ag/BFO/Pt structure device had good I-V curves, low switching voltage, a big switching resistance ratio more than 20, a good endurance with effective switching times up to 100 times above, and a better retention characteristics, after 1.8×104s, the resistance value of low resistance states and high resistance states had no significant change. The resistive switching mechanism of Ag/BFO/Pt device was simply analysised, mainly attributed to the formation and rupturing of Ag conductive filament.The BFO thin films with Ag doped were deposited by radio frequency magnetron co-sputtering technology, and resistive switching device of Ag/BFO/Ag-BFO/BFO/Pt structure were prepared, and the switching characteristics of the device were discussed. The results showed that, the Ag/BFO/Ag-BFO/BFO/Pt structure device had resistive switching effect obviously and good I-V repeatability, the switching voltage is relatively concentrated, a switching resistance ratio more than 10, a good endurance with effective switching times up to 100 times above, and a good retention characteristics, after nearly 104 s, the resistance value of low resistance states and high resistance states had no obvious change.The BFO thin films growth under different oxygen and argon atmosphere were deposited by radio frequency magnetron sputtering technology, and resistive switching device of Ti/BFO/Pt structure were fabricated, the switching characteristics of the device and the function of oxygen vacancies were studied. The results showed that, the device of Ti/BFO/Pt structure growth under argon had obvious I-V performance than the device of Ti/BFO/Pt structure growth under argon and oxygen. The former had better endurance with effective switching times up to 500 times, and a better retention characteristics, after nearly 3.6×104s,the resistance value of low resistance states and high resistance states had no significant change. These results suggested that oxygen vacancies play an important role in the device. |
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