In this letter,the Ta/HfO_x/BN/TiN resistive switching devices are fabricated and they exhibit low power consumption and high uniformity each.The reset current is reduced for the HfO_x/BN bilayer device compared with that for the Ta/HfO_x/TiN structure.Furthermore,the reset current decreases with increasing BN thickness.The HfO_x layer is a dominating switching layer,while the low-permittivity and high-resistivity BN layer acts as a barrier of electrons injection into TiN electrode.The current conduction mechanism of low resistance state in the HfO_x/BN bilayer device is space-chargelimited current(SCLC),while it is Ohmic conduction in the HfO_x device.
We demonstrate the polarization of resistive switching for a Cu/VOx/Cu memory cell.The switching behaviors of Cu/VOx/Cu cell are tested by using a semiconductor device analyzer(Agilent B1500A),and the relative micro-analysis of I-V characteristics of VOx/Cu is characterized by using a conductive atomic force microscope(CAFM).The I-V test results indicate that both the forming and the reversible resistive switching between low resistance state(LRS) and high resistance state(HRS) can be observed under either positive or negative sweep.The CAFM images for LRS and HRS directly exhibit evidence for the formation and rupture of filaments based on positive or negative voltage.The Cu/VOx/Cu sandwiched structure exhibits reversible resistive switching behavior and shows potential applications in the next generation of nonvolatile memory.
Flexible TiO2 memory devices are fabricated on a plastic substrate at room temperature. The metal-insulator-metal (MIM) structure is grown on polyimide (PI). Several metals with different ductilities, such as Al, W, Cu and Ag, are selected as electrode. The test results show that the samples have stable resistive switching behaviors, and the electric characteristics can stay stable even after the radius of substrate is bent up to 10 mm. After 103 times of substrate bend-ing, the memory cells with W as bottom electrode on PI still show stable resistive switching characteristics and low switching voltages. The set voltage and reset voltage can be as low as 0.9 V and 0.3 V, respectively.
We investigate the resistive switching characteristics of a Cu/VOx/W structure. The VOx film is deposited by radio-frequency magnetron sputtering on the Cu electrode as a dielectric layer. The prepared VOx sample structure shows reproducible bipolar resistive switching characteristics with ultra-low switching voltage and good cycling endurance. A modified physical model is proposed to elucidate the typical switching behavior of the vanadium oxide-based resistive switching memory with a sudden resistance transition, and the self-saturation of reset current as a function of compliance current is observed in the test, which is attributed to the growth pattern of the conducting filaments. Additionally, the related conducting mechanism is discussed in detail.
In this paper,the positive influence of apodization weighting method on frequency characteristics of surface acoustic wave(SAW)temperature sensor is investigated.Simulation and experiment results show that side lobe suppression abilities of the sensor can be improved by using apodization weighting which is based on Chebyshev window.Meanwhile,we find that the side lobe of the sensor can be further restrained,when the dummy electrodes are removed.Frequency-temperature characteristics of the devices are independent of the inclusion of dummy electrodes.The apodization weighted SAW temperature sensor shows great application potential in occasions with strong electromagnetic interference.
