Deposition Of ZrO Research Articles

Dynamics of processes during the deposition of ZrO2 films by controlled reactive high-power impulse magnetron sputtering: A modelling study

A time-dependent parametric model was applied to controlled reactive high-power impulse magnetron sputtering (HiPIMS) depositions of stoichiometric ZrO2 films, carried out in our laboratories, (i) to clarify the complicated dynamics of the processes on the target and substrate surfaces during voltage pulses, and (ii) to corroborate the importance of the O2 inlet configuration (position and direction) which strongly affects the O2 dissociation in the discharge and the chemisorption flux of oxygen atoms and molecules onto the substrate. The repetition frequency was 500 Hz at the deposition-averaged target power densities of 25 Wcm−2, being close to a target power density applicable in industrial HiPIMS systems, and 50 Wcm−2 with a pulse-averaged target power density up to 2 kWcm−2. The pulse duration was 50 μs. For the experimental conditions with the to-substrate O2 inlets, the deposition-averaged target power density of 50 Wcm−2, and the oxygen partial pressure of 0.05 Pa (being close to the mean value during controlled depositions), our model predicts a low compound fraction, changing between 8% and 12%, in the target surface layer at an almost constant high compound fraction, changing between 92% and 93%, in the substrate surface layer during the pulse period (2000 μs). The calculated deposition rate of 89 nm/min for these films is in good agreement with the measured value of 80 nm/min achieved for optically transparent stoichiometric ZrO2 films prepared under these conditions.

离子束溅射制备“日盲”紫外诱导透射滤光片

Solar-blind UV induced Transmission Filters(SBU-ITFs) were fabricated by ion-beam sputtering.Firstly,SBU-ITFs were designed and analyzed theoretically,and the deposition of ZrO_2,SiO_2 and Al films by ion beam sputtering was optimized.The optical constants of ZrO_2 and SiO_2 films were derived from the transmitting and reflecting spectra,and the optical constant of Al film was determined by the inversion of the variable incidence ellipsometric spectrum of a sample JGS1/SiO_2/Al/SiO_2/air(SAS).On the basis of the research,the SBU-ITFs were fabricated by using the three films above and their optical properties were measured.The measurement for SBU-ITFs shows that the peak transmittance of the filter at the 264 nm center wavelength is larger than 60%,the transmittance band width(FWHM) is about 13 nm,and the optical density in the 300-350 nm cutoff spectral region reaches to 2.6.The analysis of the transmittance shows that the main factors affecting the properties of SBU-ITFs are a slower deposition speed for Al film and smaller amount of O_2 contents remaining in the chamber during the deposition of Al film.

Design of SiO 2/ZrO 2 core–shell particles using the sol–gel process

Core–shell particles of SiO 2/ZrO 2 were developed using a sol–gel process. Spherical core particles of SiO 2, 320 nm in diameter, were initially prepared using tetraethylorthosilicate (TEOS), and then uniformly shelled with ZrO 2 nano-particles synthesized with zirconium(IV) butoxide (TBOZ). The deposition of ZrO 2 nano-particles on the SiO 2 core particles was generally promoted when increasing the H 2O and TBOZ concentrations and temperature of the sol–gel process. However, micron-sized homo-aggregates of ZrO 2 were formed above certain concentrations of H 2O and TBOZ due to self-aggregation of the nano-ZrO 2 particles. It was very interesting to discover that a chemical bonding between zirconium and silicon bridged by oxygen (Si–O–Zr bond) was developed during the formation of the ZrO 2 shell around the core particles, as the silane groups on the core particles were condensed with zirconium hydroxyl groups during the deposition of ZrO 2. XPS and FT-IR confirmed the chemical bonding of Si–O–Zr in the core–shell particles.

Deposition of ZrO 2 film by liquid phase deposition

In this study, undoped ZrO 2 thin films were deposited on single-crystal silicon substrates using liquid phase deposition. The undoped films were formed by hydrolysis of zirconium sulfate (Zr(SO 4) 2·4H 2O) in the presence of H 2O. A continuous oxide film was obtained by controlling adequate (NH 4) 2S 2O 8 concentration. The deposited films were characterized by SEM, FT-IR, XRD and DTA. Typically, the films showed excellent adhesion to the substrate with uniform particle diameter about 150 nm. The thicknesses of ZrO 2 film were about 200 nm after 10 h deposition at 30 °C. These films shows single tetragonal phase after heat treated at 600 °C. High annealing temperature (e.g. 750 °C) may result in the phase transformation of (t)-ZrO 2 into (m)-ZrO 2.

Distribution of oxygen vacancies and gadolinium dopants in ZrO 2–CeO 2 multi-layer films grown on α-Al 2O 3

Gdolinia doped ZrO 2 and CeO 2 multi-layer films were deposited on α-Al 2O 3 (0001) using oxygen-plasma-assisted molecular-beam epitaxy. Oxygen vacancies and Gd dopant distributions were investigated in these multi-layer films using X-ray diffraction (XRD), conventional and high-resolution transmission electron microscopy (HRTEM), annular dark-field imaging in scanning transmission electron microscopy (STEM), X-ray energy dispersive spectroscopy (EDS) elemental mapping and X-ray photoelectron spectroscopy (XPS) depth profiling. EDS and XPS depth profiling reveal that the Gd concentration in the ZrO 2 layer is lower than that in the CeO 2 layer. As a result, a higher oxygen vacancy concentration exists in the CeO 2 layers compared to that in the ZrO 2 layers. In addition, Gd is found to segregate only at the interfaces formed during the deposition of CeO 2 layers on ZrO 2 layers. On the other hand, the interfaces formed during the deposition of ZrO 2 layers on CeO 2 layers did not show any Gd segregation. The Gd segregation behavior at every other interface is believed to be associated with the low solubility of Gd in ZrO 2.

Metalorganic chemical vapour deposition (MOCVD) of zirconia and lead zirconate titanate using a novel zirconium precursor

The novel mixed ligand precursor Zr 2(OPr i) 6(thd) 2 (thd=2,2,6,6,-tetramethyl-3,5-heptanedionate) has been used in the deposition of ZrO 2 and Pb(Zr,Ti)O 3 thin films by liquid injection metalorganic chemical vapour deposition (MOCVD). Oxide growth was observed over a wide temperature range, from 250°C to at least 600°C. Maximum growth rates of ZrO 2 occurred between 350°C and 550°C, significantly lower than the optimum deposition temperature from the conventional Zr(thd) 4 precursor, and in a similar temperature range to optimised oxide growth from Pb(thd) 2. Consequently, the use of Zr 2(OPr i) 6(thd) 2 in combination with Pb(thd) 2 and Ti(OPr i) 2(thd) 2 leads to the deposition of Pb(Zr,Ti)O 3 with improved compositional uniformity.

Deposition of ZrO2 and Y2O3-stabilized ZrO2 from β-diketonates

The deposition of ZrO 2 and Y 2 O 3 -stabilized ZrO 2 from metalorganic β-diketonates by CVD and the evaporation behaviour of those precursors was investigated. Evaporation and deposition processes were correlated with fluiddynamical calculations and found to be in good agreement. The calculations also show that much higher growth rates than achieved until now could be expected (i.e. >1μm/min)

A high resolution transmission electron microscopy study of ZrO 2-CaO films

The structure of ZrO 2-CaO films, which were prepared by vacuum deposition and crystallized by electron beam heating, was investigated by high resolution electron microscopy. In an amorphous ZrO 2 film obtained from the deposition of pure ZrO 2, monoclinic ZrO 2 crystals which are stable below 1170°C were obtained on heating in vacuum. In a film obtained from the deposition of ZrO 2 and CaCO 3, Zr(Ca)O 2− x crystals grew in a solid solution of ZrO 2 with CaO. It was observed that, in ZrO 2-20mol.%CaO films, ordered CaZrO 3 crystals and CaZr 4O 9 (Φ 1 phase) crystals were precipitated in the Zr(Ca)O 2− x crystals. Not only the lattice orientation relationship but also the atom configuration relationship of these crystals with the Zr(Ca)O 2− x crystal were established. Calcium ion walls with anion vacancies were found along the (001), (1̄10) and (1̄11) planes in the Zr(Ca)O 2− x crystals.