Papers by Keyword: Sputtering

Abstract: The polycrystalline Ti/TiN multilayer films were deposited by magnetron sputtering. We investigated the effects of mixed discharge gas pressure, bias voltage and substrate temperature on the microstructural, interfacial, and mechanical properties of the polycrystalline Ti/TiN multilayer films. X-ray reflectivity and diffraction (XRR and XRD), and nanoindentation were used to characterize the structures and mechanical properties for the films.The period of multilayer, interface width and grain size decrease with increaseing of deposition pressure. The multilayer coating at floating voltage shows TiN (111), Ti2N (103), and TiN (200) preferred crystalline orientation, whlie those at other different substrate biases show only TiN (111) and Ti2N (103) preferred crystalline orientation. It was found that the hardness increased with increasing substrate temperature. This hardness enhancement was probably caused by the modulus difference in the interface between layer Ti and TiN or the preferred crystalline orientation TiN(111).

Abstract: In this work, it is reported the characterization of the microstructure and electric properties of ZnO:Al thin films produced by magnetron sputtering. An AZOY sputtering target (98 wt% ZnO + 2 wt% Al₂O₃) was used as source material. The microstructure, optical and electrical properties of ZnO:Al thin films were investigated and correlated with substrate deposition temperature and post-annealing temperature. It is demonstrated that the microstructural, electrical and optical properties of the as-deposited thin films are dependent on the substrate temperature. The crystalline texture of ZnO:Al was improved with temperature deposition as shown in the EBSD analysis and X-ray diffraction. ZnO:Al thin film deposited at 250 °C exhibited very good electrical conductivity, as high as 200 S^.cm^-1 with an activation energy of 5.4 meV. As substrate temperature or heat treatment temperature is increased there is an apparent blue-shift on the absorption edge of the transmittance spectra, which can be explained by the Burnstein-Moss effect.

Abstract: Nickel oxide (NiO) thin films were deposited on glass substrates at various target to substrate distances in the range of 60 to 80 mm by dc reactive magnetron sputtering technique. It was observed that target to substrate distance influenced the morphological, optical and electrical properties of the deposited films. The optical results revealed that the optical transmittance of the films increased with increasing the target to substrate distance upto 70 mm, thereafter it was decreased. The increase in transmittance of the films was due to an increase in size of the grains. The NiO films exhibited an optical transmittance of 60 % and direct band gap of 3.82 eV at target to substrate distance of 70 mm. The films showed high electrical resistivity of 37.3 Ωcm at target to substrate distance of 60 mm and low electrical resistivity of 5.1 Ωcm at target to substrate distance of 70 mm. At high target to substrate distance of 80 mm the electrical resistivity of the film was increased.

Abstract: AZO thin films were deposited using a magnetron sputtering system with an AZO target (with 3wt% Al2O3) on polyethylene terephthalate (PET) substrates with pre-strain. The effect of sputtering power on the optical and electrical properties of AZO films was investigated. For samples deposited on pre-strained PET substrates, X-ray diffraction was used to determine the c-axis orientation of AZO films deposited at 60, 80, and 100 W. Results show that resistivity decreased with increasing sputtering power, which might result from the better crystalline structure and fewer grain boundaries obtained at high power. The transmittance increased when the power was increased from 60 to 100 W. The absorption edge thus decreased for AZO film deposited at 100 W.

Abstract: Fabrication of micro and nanoscale components are in high demand for various applications in diversified fields that include automotive, electronics, communication and medicine. Focused ion beam (FIB) machining is one of the techniques for microfabrication of micro devices. This paper presents a review of FIB machining technology that include its parameter, responses, its important component systems, as well as the fundamentals of imaging, milling (etching) and deposition techniques. The application of FIB in micromachining is also presented.

Abstract: High Tc superconducting tapes based on YBCO Coated Conductor have been extensively studied to develop the processing techniques for application. In this paper, two self-designed reel-to-reel deposition systems (Sputtering and PLD) were installed. Continuous deposition of multi-layer CeO2/YSZ/Y2O3 buffer layers were carried out on biaxially textured NiW substrate using reactive sputtering. YBCO films were coated on the CeO2/YSZ/Y2O3 buffered NiW substrate by continuous PLD subsequently. To achieve high current carrying capacities, combinations of various deposition conditions were explored. X-ray diffraction measurements show good in-plane and out-plane texture in buffer layers and YBCO films. The transition temperature of the YBCO was 89 K and the critical current is over 50 A at 77 K in 1 meter long YBCO tapes.

Abstract: We have found that deposited film can be crystallized without the post-annealing treatment but with the simultaneous ion-irradiation during sputter-deposition at very low substrate temperature. The present paper reviews the low temperature crystallized TiNi films deposited by the above technique. An RF magnetron sputtering apparatus equipped with separate confocal sources as well as with a heating and ion-irradiating system for substrates was used to make the films crystalline. Without using the ion-irradiating system, the films deposited on ambient-temperature substrate have been amorphous. However, crystallized film is deposited even at 353 K of substrate temperature with using the system. Appropriate ion-irradiation is considered to be help to crystallize the film at low substrate temperature. Broad and doublet X-ray diffraction profile of the film, which was diffracted from B19’ and/or R phase, was recorded between 42 degree to 45 degree in 2 theta. The crystallized film deposited on a polyimide sheet was cut into the shape of a double-beam cantilever and the ends of the two beams were connected to an electrical power supply. The cantilever shows a repeatable two-way motion by electrical cycle of 0.1 Hz at room temperature.

Abstract: Structural and optical properties of MgxZn1-xO (x=0.23) thin films grown by radio frequency (R.F.) magnetron sputtering and annealed with different temperature (from 100°C to 400°C) are reported. The films were single-phase, highly c-axis oriented and wurtzite structure. The transmission spectra, recorded in the visible range, reveal a high transmission coefficient (about 95 %) in the obtained films. Besides, when the annealing temperature is 100°C, the crystalline grains are smooth, compact and uniformly distributed. As the annealing temperature increases from 100°C to 400°C, the crystalline grains get larger, but the annealing temperature does not influence optical transmittance obviously.

Abstract: In this study, Cu(In,Ga)Se2 (CIGS) thin films were deposited onto bi-layer Mo coated soda-lime glass by sputtering a chalcopyrite CIGS quaternary alloy target. The influence of sputtering power and substrate temperature on the characterization of CIGS precursor films was investigated. Experimental results demonstrate that the CIGS quaternary target has the characteristics of chalcopyrite structures. The samples deposited at a sputter power of 1.5 W/cm2 (both as-deposited and after annealing) exhibited superior uniformity, and the phenomenon of composition loss resulting from annealing was not drastic. The composition distribution of as-deposited film produced at a substrate temperature 373 K approached that of ideal stoichiometry.

Abstract: Magnetostrictive thin films of the ternary compound (Tb_yDy_1-y)xFe_1-x have been prepared by magnetron sputtering from a Terfenol D target onto both room-temperature and high-temperature substrates (T_S<550 °C). The aim is to select the deposition parameters of this highly magnetostrictive material in order to optimize its magnetic response. Films prepared on room-temperature substrates were amorphous and those deposited at high temperatures have a microstructure consisting of small grains of RFe₂ compound and some RE oxide phases. Deposition temperatures around 550 °C promotes in-plane orientation of (220) and (311) planes of RFe₂ phase. The magnetization measurements performed at room temperature showed that depending on the processing conditions the material changes from a soft magnetic behavior with perpendicular anisotropy to a two phase system with both hard and soft magnetic phases.