| The Zr0.5Hf0.5O2thin film was deposited on Pt substrate by RF magnetron sputtering，andthe Pt/Zr0.5Hf0.5O2/Pt capacitor was also prepared. The I-V characteristic curves weremeasured at30℃,40℃,60℃,80℃,100℃,120℃,140℃and160℃respectively.The conduction mechanism of the MIM structure capacitor was discussed in order to analyzethe electrical transportation properties and mechanism of the Zr0.5Hf0.5O2thin film. Theresults of X-ray diffraction spectra (XRD) show that the films is between polycrystalline andamorphous.In the analysis of the I-V characteristic curves, we found a large amount of electriccharge traps in the Zr0.5Hf0.5O2thin film using TAT, T-FAT and Pool-Frenkel effect completethe electronic transportation.Amorphous indium gallium zinc oxide (In-Ga-Zn-O) thin films were deposited ontoglass substrates at room temperature by RF magnetron sputtering. The impacts of differentanneal temperatures and deposition powers on the structure, electrical and opticscharacteristics have been investigated systemically. In the study of the different annealtemperatures from300℃to500℃，the results of X-ray diffraction spectra (XRD) show thatthe films before and after annealed were amorphous. Optical transmission spectra of theIn-Ga-Zn-O samples demonstrate that all the films present a high transmittance of above80%in the visible range form500to800nm. The electrical resistivity of In-Ga-Zn-O films is thelowest at350℃and the optical band gap of the films is as many as3.91eV. In the study of thedifferent deposition powers from80W to150W, the results of X-ray diffraction spectra (XRD)show that the films with different power were amorphous. All the films present a hightransmittance of above90%in the visible range form500to800nm. The electrical resistivitydecreases gradually as the deposition power increases from80W to150W. The optical bandgap of In-Ga-Zn-O films decreases with the increase of deposition power.The work in this letter reports a fully transparent resistive random access memory(TRRAM) device fabricated by radio frequency (RF) magnetron sputtering with aα-IGZO/Zr0.5Hf0.5O2/α-IGZO structure and its resistive switching properties. The results of X-ray diffraction spectra (XRD) show that the films were amorphous in this device. Thefabricated device gets a transmittance of about87%(including the substrate) in the visibleregion (400-800nm wavelength). The highest number of conversions between high resistancestate (HRS) and low resistance state (LRS) can be reached more than120times, and theON/OFF ratio (the ratio between the high resistance state and the low resistance stateresistance value) up to6times, and the retation of the device did not change significantly after12hours continuous testing under0.5mV DC voltage. Then the conduction behavior of theTRRAM device is also discussed in order to explain the mechanism of the resistance swiching.It seems that changes of the effective Schottky barrier height, which is due to the migration ofoxygen vacancies in the zirconium and hafnium oxide thin film, are responsible for theresistance swiching. |
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