Papers by Keyword: RF Magnetron Sputtering

Abstract: Structural and mechanical behavior of thin hydroxyapatite (HA) films deposited via radio-frequency magnetron sputtering on AZ91D magnesium alloy was investigated. Nanoindentationwas employed to evaluate nanohardness and Young’s modulus of the uncoated and HA-coated AZ91 magnesium alloy. The HA-coated AZ91D magnesium alloy exhibited a higher hardness of 7.1 GPa and a higher modulus of 86 GPa compared withthe uncoated substrate revealing a strong load-bearing capacity.

Abstract: Titanium nitride (TIN) films were prepared by using rf magnetron sputtering technique. The films were deposited by a pure N₂ plasma sputtering. Their mechanical properties, such as nanoindentation hardness, friction coefficient, and wettability have been investigated. XRD studies revealed that the orientation of TiN films changes toward the (111) orientation with decreasing working pressure due to a strong compressive stress during deposition . The strongest TiN(111) orientation is found when the film is deposited at working pressure of 1pa. This film shows a largest hardness of 15 GPa and a smallest friction coefficient of 0.17. This film was also found to be accompanied by a water-repellent surface with a water contact angle more than 100^°

Abstract: ZnO_1-x thin films were deposited by RF magnetron sputtering on conducting silicon wafers at room temperature with ZnO_n (n≤1) target under an atmosphere of O₂/Ar ratio varying from 0 to 2.0. The correlation between composition, structure and electrical resistivity of the obtained films was investigated. X-ray diffraction analysis revealed that the prepared würtzite ZnO_1-x films had c-axis preferential growth orientation. When the O₂/Ar ratio was lower than 0.5, the main form of defects in the films was oxygen vacancy; when it was 0.5, the composition of the film approached to the stoichiometric ZnO and had the least number of defects; after that, the main type of defects in the films was interstitial zinc. Thus, with increasing O₂/Ar ratio, the electrical resistivity of the films increased first and then decreased.

Abstract: In this paper, the TiO₂ film and Ti/TiN/TiO₂ multilayers were prepared by anodic oxidation and RF magnetron sputtering technology on surface of NiTi shape memory alloy, respectively. The structure and surface morphology of films were systematically studied by X ray diffracmeter (XRD) and scanning electron microscope (SEM); blood compatibility was researched by kinetic clotting time and platelets adsorption experiment. The result showed that, blood compatibility was improved in varying degrees after surface treatment. And the multilayer which was deposited on NiTi alloy by RF reactive magnetron sputtering after the method of constant voltage anodization had optimal Anti-clotting properties.

Abstract: P-type transparent conducting SnO thin films were directly fabricated using RF magnetron sputtering. The electronic properties of the SnO thin films were enhanced by Na ion implantation and annealing at 200°C. The growth and implantation conditions were systemically investigated. The electronic properties, optical properties, microstructure and surface morphologies of the films were characterized. It was observed that the structure of the Na-doped SnO films was crucial to improving their p-type conductivity.

Abstract: Charge-trapping memories such as SONOS and MONOS have attracted considerable attention as promising alternatives for next-generation flash memories due to dielectric layer’s scalability, process simplicity, power economy, operation versatility. Nevertheless, the continued miniaturization of the devices forces an application of high-k dielectrics. In this work high-k stacked dielectric structures based on the combination of Hf-based and SiN_x materials were fabricated. Their structural and electrical properties versus deposition conditions are studied by means of FTIR-ATR and high-resolution TEM techniques. All samples demonstrated smooth surface (roughness below 1 nm) and abrupt interfaces between the different stacked layers. No crystallization of Hf-based layers was observed after annealing at 800°C for 30 min, demonstrating their amorphous nature and phase stability upon annealing. Electrical characterization was carried out for all samples through capacitance-voltage (C-V) measurements of MIS capacitors. Uniform C-V characteristics were measured along the samples for all stacks. Besides, significant flat-band hysteresis due to charging of the stacks caused by carrier injection from the substrate was observed for the structures with pure HfO₂ layers.

Abstract: Amorphous Nb-doped TiO₂ thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb₂O₅-TiO₂ sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb₂O₅ pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.

Abstract: Fabrication and performance of metal-semiconductor-metal (MSM)–type intrinsic zinc oxide-coated, aluminium-doped ZnO nanorod array-based ultraviolet photoconductive sensors were reported and discussed. The Al-doped ZnO nanorod arrays were prepared using sonicated sol-gel immersion method. The coating process of intrinsic ZnO onto Al-doped ZnO nanorod arrays was performed using radio-frequency (RF) magnetron sputtering at different deposition times varying from 0 to 10 min. We observed that responsivity of the sensors decreased with increasing intrinsic ZnO deposition time, decreasing from 4.81 A/W without coating to 1.37 A/W after 10 min of coating. Interestingly, the sensitivity of the sensors improved with intrinsic ZnO coating, having a maximum value of 19.0 after 1 min coating.

Abstract: The effect of the nitrogen dilution on the optical and vibrational properties of amorphous silicon carbide (a-SiC) and silicon oxycarbide (a-SiCO) layers have been studied. The films were prepared by radio frequency (rf) reactive magnetron sputtering using an atmosphere mixture of argon (Ar) and nitrogen (N₂). The oxygen (O₂) was incorporated according to the base pressure used of each deposition process. The optical and vibrational properties of the films were characterized by means of UV/VIS transmittance measurements and Fourier transform infrared spectroscopy (FTIR), respectively. A relationship between the variation of the optical bandgap and the increase or quench of vibrational modes is established. This analysis reveals that the increase of nitrogen in both host matrices a-SiC and a-SiCO induced the formation of C=N and C N bonds thus reducing the bandgap of the material.

Abstract: A nanocomposite TiAlBN (n-TiAlBN) coating has been successfully deposited via RF magnetron sputtering by varying the nitrogen-to-total gas flow ratio (R_N) at a substrate temperature of 300 °C. The coating was deposited on AISI 316 substrates using a single Ti-Al-BN hot-pressed target. The crystal phases, grain size and chemical composition of the coatings were measured using the glancing angle X-ray diffraction analysis (GAXRD) and X-ray photoelectron spectroscopy (XPS). The grains size of the n-TiAlBN coating was found to be within the range of 3.5 to 5.7 nm calculated using Scherrer’s formula. The n-TiAlBN coating reached a nitride saturated state at a higher R_N (e.g >15%) with the amount of boron concentration to be around 9 at. %. Further, reducing the R_N (e.g. 5%) has increased the boron concentration to 16.17 at. %. This paper shows that by carefully control the nitrogen-to-total gas flow ratio (R_N) in the n-TiAlBN coating, it indeed gives a significant effect on its crystallographic structure, grain size, and chemical compositions.