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Purpose – The purpose of this paper is to report the effect of sputtering time on the electrical and physical properties of ZrOx. ZrOx (measured thickness is ranging from 20.5 to 51.3 nm) thin films as gate oxide materials are formed by metal deposition at different sputtering time and thermal oxidation techniques. Design/methodology/approach – Zirconium is deposited on silicon substrate at three different sputtering time; 30-, 60- and 120-s continued with an oxidation process conducted at 500°C for 15 min to form ZrOx thin films. High-resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy and electrical characterizations were used to examine the properties of the thin film. Findings – A broad ZrOx peak lies in between 26° and 31° from HR-XRD is presumed as the effect of small thickness of ZrOx and or the ZrOx is still partially crystalline. FTIR spectroscopy results suggested that besides ZrOx, SiOx interfacial layer (IL) has also formed in all of the investigated samples. As the sputtering time increases, hysteresis between the forward and reverse bias of capacitance-voltage curve has reduced. The lowest leakage current density and the highest oxide breakdown voltage have been demonstrated by 60-s sputtered sample. These may be attributed to a lower effective oxide charge and interface trap density. The extracted dielectric constant (κ) of these oxides is ranging from 9.4 to 18, in which the κ value increases with the increase in sputtering time. Originality/value – ZrOx thin film which was fabricated by sputtering method at different sputtering time and thermal oxidation techniques showed distinctive electrical results. SiOx IL formed in the samples. [ABSTRACT FROM AUTHOR]

Cerium oxide (CeO2) solution was prepared by cerium(lIl) acetylacetonate hydrate, methanol, and acetic acid as the starting materials via the metallorganic decomposition (MOD) method. Postdeposition annealing was performed Onto the MODderived CeO2 films deposited onto ntype Si substrates at different temperatures (600, 800, and 1000°C) under the flow of argon gas. A slow cooling rate was then accomplished for samples to cool down to room temperature. Four orientations [III), (200), (220), and (311)] of CeO2 films were revealed by Xray diffraction analysis as well as csCe2O3 and cerium silicate (Ce2Si2O7). Epitaxiallike behavior was shown in the sample annealed at 600°C due to the (200)oriented CeO2 film, and the dominance of this plane ceased with the increase in annealing temperature. A negative voltage shift was observed in all of the samples, indicating that positive oxide charges were trapped in the oxide as a result of the presence of oxygen vacancies. An interface trap density was extracted from the capacitancevoltage measurement, and it was related to the current densityvoltage characteristics of the investigated samples. The lowest density was perceived by the sample annealed at 1000°C due to the increment in the Ce2Si2O7 layer, reduction in total interface trap density, and effective oxide charge. 0 [ABSTRACT FROM AUTHOR]

The effects of oxygen on the superconducting properties of thin films of MgB2 have been studied. It is found that after annealing for short times in flowing O2 at 400 °C, complex oxides of Mgx(ByO)z are formed that cause a “two-step” behavior in the resistively determined superconducting transition. These oxides are not stable at room temperature and decay into MgO and B2O3 precipitates. As the complex oxides decay so the original Tc behavior of the films is restored to its preoxygenation level. [ABSTRACT FROM AUTHOR]

The microwave power and frequency dependence of the surface resistance of MgB[sub 2] films and powder samples were studied. Sample quality is relatively easy to identify by the breakdown in the ω² law for poor-quality samples at all temperatures. The performance of MgB[sub 2] at 10 GHz and 21 K was compared directly with that of high-quality YBCO films. The surface resistance of MgB[sub 2] was found to be approximately three times higher at low microwave power and showed an onset of nonlinearity at microwave surface fields ten times lower than the YBCO film. It is clear that MgB[sub 2] films are not yet optimized for microwave applications. [ABSTRACT FROM AUTHOR]

MgB[sub 2] thin films were cold grown on sapphire substrates by pulsed laser deposition followed by postannealing in mixed, reducing gas, Mg rich, Zr gettered, environments (pO[sub 2] ∼ 10[sup -24] atm) at 750 and 950 °C. The films had T[sub c] in the range 29–34 K, J[sub c] (20 K, H = 0) in the range 3 × 10[sup 4] − 3 × 10[sup 5] A cm[sub -2], and irreversibility fields H* at 20 K of 4–6.2 T. An inverse correlation was found between T[sub c] and H*. The films had grain sizes of ∼0.1–1 µm and a strong biaxial alignment was observed in the 950 °C annealed film. (111) oriented MgO was also observed. Mg coating of films during crystallization appeared to improve film T[sub c]. [ABSTRACT FROM AUTHOR]

Abstract: Lanthanum cerium oxide (LaxCeyOz) precursor was prepared using metal-organic decomposition method. The effects of post-deposition annealing temperatures (400–1000°C) and annealing time (15–120min) in argon ambient on physical properties of the deposited film were investigated. X-ray diffraction was employed to detect the presence of phase and crystal orientation in the films. Williamson–Hall plot was used to determine the grain size and microstrains of the film. The grain size increased with the increase of annealing temperature and time while microstrains showed an inverse relationship. High resolution transmission electron microscopy (HRTEM) revealed the formation of three layers on top of the Si substrate. [Copyright &y& Elsevier]

Abstract: Cerium oxide (CeO2) precursor, prepared by metal-organic decomposition method, was spin-coated on n-type 4H-SiC substrate. Effect of post-deposition annealing (600, 800, and 1000°C) in argon ambient on physical properties of the deposited film (∼110nm) was investigated. Refractive index (n f ) of the film was measured by ellipsometer. Lorentz–Lorenz law was applied to estimate the film density (ρ f ). n f and ρ f were increased with increasing annealing temperature. Film with defect-free surface had been revealed under field-emission scanning electron microscope. In order to study topography and surface roughness of the annealed oxides and SiC surfaces, atomic force microscope was used. The film showed an increment in surface roughness when the annealing temperature was increased. X-ray diffraction (XRD) was employed to detect the presence of crystalline phases and orientations in the films. Williamson–Hall plots were constructed from XRD line broadening, in which grain size (D) and microstrains were determined. Opposite relationship between D and microstrains was observed with the increase of annealing temperature. Coefficient of texture was calculated and used to measure preferred orientation of the film. All of the films annealed at different temperatures demonstrated (200)-preferred orientation. [Copyright &y& Elsevier]

Abstract: Raman spectra of a series of thin films of the superconductor MgB2 have been measured as a function of the T c of the films. An interesting correlation is observed between the Raman shift of the E 2 g mode and the T c. We propose a mechanism for the T c reduction, which has consequences for the behaviour of the two superconducting gaps in MgB2 for samples of very reduced T c (≤19K). Additionally, the effects of oxygenation on the properties of MgB2 have been studied in order to develop an understanding of the effects of structural distortion in this material. [Copyright &y& Elsevier]