Papers by Keyword: RF Sputtering

Abstract: Carbon doped aluminum oxide co-doped with magnesium (Al₂O₃:C:Mg) thin films were deposited using radio frequency magnetron sputtering method on Si (100) substrates. The deposition chamber temperature was manipulated to allow control over the crystalline phase. The crystalline phase of deposited thin films were determined by x-ray diffraction (XRD) technique. Slight change in crystallite size was observed with respect to the increasing deposition chamber temperature. Fourier transform infrared (FTIR) analyses indicated a negligible interfacial SiO₂ growth during deposition. Transmission spectra of FTIR showed the bond and functional group of deposited thin films.

Abstract: Solar hydrogen (H₂) generation from water electrolysis is a key target for the development of sustainable hydrogen economy for future energy system. The formation of self-organized and highly ordered titania (TiO₂) nanotubes is essential for high efficiency in photoelectrochemical (PEC) water electrolysis application. Based on our preliminary studies, highly ordered TiO₂ nanotubes were successfully synthesized through anodization of titanium (Ti) foil in ethylene glycol (EG) containing 5 wt% of ammonium fluoride (NH₄F) and 5 wt% of hydrogen peroxide (H₂O₂) at 60 V for 1 h. However, an obvious hindrance to the widespread use of TiO₂ nanotubes as a photoelectrode in PEC water electrolysis system is its poor visible light response and rapid recombination of photo-induced electron/hole pairs. Thus, continuous efforts have been exerted to improve the efficiency of PEC water electrolysis by incorporating an optimum content of W⁶⁺ species into TiO₂ nanotubes. In the present study, a practical technique of radio frequency (RF) sputtering was selected to incorporate W⁶⁺ species into TiO₂ lattice. It was found that TiO₂ nanotubes sputtered at high energy of 50 W for 30 sec demonstrated a maximum photocurrent density of ~ 2.4 mA/cm² with photoconversion efficiency ~ 6 %.

Abstract: PZT thin film was fabricated by using RF-sputtering process, and platinum was used as bottom electrodes. The sputtering gases were Ar：O2＝25：0 sccm, Ar：O2＝20：5 sccm, or Ar：O2＝15：10 sccm. After sputtering, the PZT film was annealed for 5 minutes under O2 gas environment and at the temperature of 600 0C, 650 0C, 700 0C or 750 0C. To judge the quality of the deposited PZT film, its physical properties and electric properties were evaluated. The results indicate that the best crystallization temperature of PZT thin film is about 700 0C. Also, the roughness of the PZT thin film becomes larger with the increasing of annealing temperature. By adding more oxygen in the sputtering gas, one could have better crystallization of the PZT film. As for the electrical properties, the leakage current of PZT thin film increases with the increasing of annealing temperature. Furthermore, the ferroelectric property is affected by the crystallization amount of perovskite, the thickness of PZT thin film, and the diffusion situation between the bottom electrode and the PZT film.

Abstract: In this paper, we used RF sputter to deposit the ZnO seed layer of 0.6 μm in thickness, which was then immersed in zinc nitrate hexahydrate [Zn(NO3)2•6H2O] and hexamethylenetetramine (C6H12N4) mixture solution of different concentrations for the growth of ZnO nanorods by hydrothermal method. After annealing at different temperatures, thermal field emission scanning electron microscope (TFSEM) was used to observe the arrangement and growth of ZnO nanorods. We found the concentration of the mixture solution of C6H12N4 and Zn(NO3)2•6H2O would affect the thickness and crystallization of ZnO nanorods, and the annealing temperature would change their columnar arrangement structure. The arrangement structure of the ZnO nanorods grown in the mixture solution of 0.2M concentration had more gaps and pores. Under this condition, we successfully fabricated a dye-sensitized solar cell (DSSC), of which the performance could be further improved by using ZnO nanorods prepared by many different methods.

Abstract: Large surface area nanostructural IrO_x films were deposited on stainless steel substrates by reactive radio frequency magnetron sputtering using Ir metal target. The structural and spectroscopic properties of the nanostructural IrO_x were characterized. The micrographs of field emission scanning electron microscopy showed the formation of folded leaves with chiffon-like structure for the as-deposited samples. X-ray photoelectron spectroscopy analysis provided the information of the oxidation states and the stoichiometry of IrO_xNL. Raman spectra revealed the amorphous-like phase of the as-deposited nanostructural IrO_x. The chiffon-like structure provides ultra-high surface area for electrical charge storage which makes the IrO_xNL as an attractive candidate for the supercapacitor application.

Abstract: We report the deposition of aluminium doped zinc nitride film (Al-Zn₃N₂) on glass substrates by RF sputtering. Thermal oxidation of the film under different annealing temperature (500°C to 600°C) was carried out. Structural and electrical properties of the annealed films were investigated. XRD analysis showed that Al-Zn₃N₂ film was successfully converted into Al-N zinc oxide (ANZO) at 500°C. I-V characteristics of the films were measured and the lowest estimated resistivity of the films of 4kΩ.cm can be achieved at 600°C.

Abstract: Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10^-8A/cm², respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.

Abstract: In this study, the effects of La and V doping on Bi₄Ti₃O₁₂ (BLTV) ferroelectric thin films deposited on ITO/glass substrates using rf magnetron sputtering were produced and investigated. The effect of oxygen concentration and RF power on the physical and electrical characteristics of BLTV thin films was determined. The physical characteristics of BLTV thin films were obtained by the XRD pattern, SEM and AFM. The variations of crystallization, surface roughness and thickness of BLTV thin films were discussed. The electrical properties of BLTV thin films deposited under various parameters were measured by the HP4156C.

Abstract: We have investigated the structure and ferroelectric properties of the Bi_3.25La_0.75Ti₃O₁₂ (BLT) thin films on SiO₂/Si substrate fabricated by sol-gel method. We used the BLT films were annealed at various temperatures of 600, 650, and 700°C for one hour by conventional furnace annealing (CTA). The temperature dependence of leakage currents densities of ferroelectric BLT thin films. The crystalline structure of the prepared BLT thin films was analyzed by X-ray diffraction (XRD). Field emission scanning electron microscopy (FESEM) was used to observe the film thickness and the surface morphology including grain size and porosity. The leakage current density and capacitance of thin film were measured by HP4156C.

Abstract: Ga doped Z_nO (GZO) films of different concentrations (1, 2 and 4 mol%) have been deposited on glass substrates by RF magnetron sputtering. The grown layers at room temperature have been subjected to structural, optical and electrical characterization. It has been found that 2 mol% Ga doped ZnO has best structural, optical and electrical properties which has been used as anode layer for the fabrication of Organic Light Emitting Diode (OLED). The Zn0.98Ga0.02O film was then deposited at a lower working pressure of 0.015 mbar to obtain a good carrier concentration. The OLED structure has been fabricated with best GZO as anode layer, [N, N*-Diphenyl N, N*-Di-p-Tolylbenzene-1] as hole emitting layer and (Alq3) as electron transport layer. The fabricated OLED device has been subjected to current-voltage characteristics.