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The ultra-thin tin doped crystalline indium oxide (ITO) films (≤50 nm) were successfully deposited by a 3-dimensionally confined magnetron sputtering source (L-3DMS) at the temperature lower than 100 °C. The resistivity and the mobility of the ultra-thin ITO films deposited at a low processing temperature were about ~5 × 10−4 Ω · cm and >30 cm2/Vs, respectively, for the thickness of 30 nm. The high quality of the ultra-thin ITO films deposited by L-3DMS is believed to be related to the improved crystallinity with oxygen vacancies of the ITO films by high density plasma and low discharge voltage of the L-3DMS which enables the formation of a crystalline structure a low processing temperature.

The purpose of this study was to apply a Ti film to various substrates for use in biomaterials. By forming TiO 2 nanotubes on a film, the biocompatibility of the TiO 2 nanotube and its ability as a carrier can be applied to a variety of materials for use within diverse applications. In this work, we present the fabrication of a self-organized TiO 2 nanotube layer that was grown from flat and thin sputter-deposited titanium films on a Si (100) substrate by plasma electrolytic oxidation, and evaluated the use of this material for the release of gentamicin. This resulted in TiO 2 nanotubes with lengths ranging from about 200 to 400 nm, as confirmed in a cross-sectional view. Operation at a low temperature was a key to achieving self-organized, time-dependent growth of the TiO 2 nanotube layer from the thin film on a Si substrate. The drugs were then pipetted on the formed nanotubes and their release was evaluated. The results showed that there was adequate drug release from the samples which suggests that they have the potential to be a drug carrier.

A silver-containing titanium oxide nanocomposite layer was synthesized on a commercially-pure titanium (cp-Ti) substrate by a reactive pulsed DC magnetron sputtering. The oxygen partial pressure was controlled to improve the mechanical and antibacterial properties and to sustain the biocompatibility for the implantable devices. The films were analyzed by a series of techniques including FESEM, HR-XRD, and XPS. The film's mechanical properties were determined by a nano-indenter and scratch tester. Antibacterial activity was assessed by the silver ion release test and the plate-counting method used against Staphylococcus aureus. An agar diffusion test was performed to evaluate the cytotoxicity in terms of the biocompatibility. Silver nanoparticles mainly existed at the surface region and these contributed to improved mechanical properties, such as increased hardness and a lower friction coefficient. Moreover, the relationship between silver ion release and the antibacterial activity of the films was explored. The results confirmed that the magnetron sputtered silver-containing titanium oxide nanocomposite coatings have good mechanical properties and are applicable as an efficient antibacterial layer with sustained biocompatibility.

Time-resolved optical emission spectroscopy is used to investigate the discharge of the RF pulse sputtering of copper. The time integrated emission of a neutral copper atom in RF pulse sputtering was found to be superior to emission in continuous mode. The increase stemmed from the concentration of the power in the sharp pulse at the breakdown of the discharge. The integrated emission reached its maximum at 50% duty ratio. A sudden drop in the copper emission in continuous mode from that of a 98% duty ratio was correlated with an absence of the power peak of the pulse mode.

We deposited MoSiN multilayer films using a MoSi2 target via pulsed-DC and radio-frequency (RF) magnetron sputtering methods. For the fabrication of the Ti-covered Si(100) substrate, we also grew Ti layers via the RF magnetron sputtering method. To improve the mechanical properties of the as-grown MoSiN thin films, argon and nitrogen plasmas ignited by RF and pulse DC under vacuum conditions were also used with a total pressure of 0.7 Pa, a substrate bias of −100 V, and a substrate ion current density of 1.5 mA/cm2. The as-grown MoSiN films were investigated for hardness (Gpa) and macro-stress(s) properties, and the relationship between film composition and micro-structures was analyzed using x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). The maximum hardness and stress values of the MoSiN films were 32 GPa and −2.5 GPa, respectively, depending on variations of substrates and reactive gas.

The density of ground state and metastable Ti atoms were measured in a magnetron sputtering reactor with a 10 cm diameter Ti target by using resonant optical absorption spectroscopy. Experiments were conducted under various discharge parameters, namely the discharge current (0.2 A to 1.2 A) and the distance from the target (2 cm to 12 cm) under two working pressures (0.5 Pa and 4 Pa). The results were compared with previous results for a smaller magnetron source with a 5 cm diameter target. The Ti densities were as follows: [Ti]≈1011 cm−3, [Tim]=1010 to 1011 cm−3 for 0.5 Pa and [Ti]≈[Ti∞]=1010 to 1012 cm−3 for 4 Pa. The portion of Ti metastables in the discharge increases by a factor of approximately 2 as the working pressure increases.

Brasses are the most widely used copper-based alloys because of the good corrosion resistance, formability, high strength and excellent hot-working properties. However, dezincification occurs when one or more components of an alloy are more susceptible to corrosion than the rest and, as a result, are preferentially dissolved. In order to enhance the corrosion resistance, the brasses were exposed to pulsed DC oxygen plasma with various frequencies. The corrosion behavior of plasma oxidized brasses (POBs) with various pulse frequencies was investigated by electrochemical methods (potentiodynamic polarization test, electrochemical impedance spectroscopy) and surface analyses (X-ray diffraction, scanning electron microscopy). Particular attention was paid to the effects of pulse frequency on the corrosion properties of POBs. From the results of electrochemical test, it was found that the oxidized brass under the condition of 1.5 Torr oxygen pressure and 20 kHz frequency was effective in improving corrosion resistance. This was attributed to the protective oxidized layer (ZnO).

The synthesis of W–Ti–C multi phase film and the relationship between microstructure and composition were studied. W–Ti–C multi phase films, containing the W2C, TiC and WTiC, were successfully synthesized by hybrid system which was composed of arc ion plating (WC) and reactive magnetron sputtering (TiC). Chemical composition of each film was analyzed by Auger Electron Spectroscopy (AES). Also, microstructure of the W–Ti–C film was characterized by using X-ray diffraction (XRD) and Raman spectrometer. With increasing titanium composition, film phase transferred from W2C to WTiC and film hardness was decreased. In case of increasing carbon composition, TiC based multi phase film was formed at low carbon content and amorphous carbon or DLC (Me-C:H) film was formed at high carbon content. The film hardness was increased when the ratio of ‘(W + Ti) / C = 1’ and DLC was formed. Base on these results, we could present simple ternary diagram of W–Ti–C film as WTiC based, TiC based and amorphous carbon based multi phase films formation region.

We have treated the surfaces of Al, SUS and Cu metals using an atmospheric-pressure plasma jet generated by nitrogen and oxygen gases under the atmospheric pressure at room temperature. The plasma ignition occurred by flowing mixed gases between two coaxial metal electrodes, and the voltage was applied with impulse type and 16–20 kHz frequencies. The treated surfaces were basically characterized by means of a contact angle analyzer for the activation property on their surfaces. From the results of XPS, FE-SEM, OES and AFM, we could confirm that the main phenomena such as the reactive etching and oxidation were observed on their surfaces as well as even the aggregation of particles by the activated atoms, radicals and metastable species in the plasma space. However, all treated surfaces contained only oxygen and carbon without nitrogen, even though the excited nitrogen species were generated in the plasma due to its higher reactivity than oxygen ones observed in the OES data. The aging effect on the duration time of the surface energy, moreover, was also studied because of the production cost on the industrial applications in addition.

Summary form only given. Biological integration of implant to surrounding tissue is important process as it determines its clinical success and attraction of bone cells. Also, in order to reduce the problems of implant-related infections, many kinds of the surface treatment on titanium have been proposed. The formations of TiO 2 nanotubes on the titanium have been widely studied to improve the biocompatibility of the surface, and silver nanoparticles have been known to exhibit the antibacterial efficacy. The purpose of this study was to carry out surface treatment on titanium and observe response of human periodontal ligament (hPDL) cells using combination of nanotube formation and silver nanoparticles treatment.

Summary form only given. TiO 2 nanotubes are biocompatible and many studies have been carried out for their biotechnological applications, especially in relation to drug carriers. The purpose of this study is to apply TiO 2 film on the variety of metal substrates that could be used as biomaterials, and by forming various depth of nanotubes on the films, biocompatibility of the TiO 2 nanotube and its ability as a carrier is applied to variety of materials according to various purposes. In this work, we present the fabrication of self-organized TiO 2 nanotubes layer that was grown from flat and thin sputter-deposited titanium (Ti) films on Si (100) wafer.

Summary form only given, as follows. It is well known that thin film growth and surface morphology can be substantially modified by ion-bombardment during the deposition. This is particularly important in case of thin-film deposition at low temperatures where the film growth occurs under highly nonequilibrium conditions. An attractive way to promote crystalline growth and surface morphology is deposition of additional energy into the surface of the growing film by bombardment with hyperthermal particles. We deposited crystalline Ti and TiN thin films on Si substrate by magnetron sputtering method with grid. Its thin films were highly smoothed and dense as increasing grid bias. In order explore the benefits of a bombardment of the growing film with high energetic particles, Ti and TiN films were deposited on Si substrates by an imbalanced magnetron sputter source with attached grid assembly for energetic ion extraction. Also, we have studied the variation of the plasma states for the feedback control of nucleation and growth behavior by Langmuir probe and Optical Emission Spectroscopy (OES). The epitaxial orientation, microstructual, optical characteristics and surface properties of the films were analyzed by XRD, SEM, ellipsometry and AFM.

Summary form only given, as follows. Magnetron sputtering is a broadly used process for coating thin films for display applications, semiconductor applications, hard coatings, decorative coatings, optical coatings, and so on. In order to enhance the film properties and deposition rate various magnetron sputtering sources have been developed such as dual magnetron sputtering, ionized magnetron sputtering, grid assisted magnetron sputtering, and so on. We have developed high efficiency magnetron sputtering sources. In this study, we investigated of spectroscopic study for ionization enhancement in the magnetron sputtering process with a solenoid coil. The sputtering cathode used in the experiment is a unbalanced magnetron sputtering source with a Ti target which is coupled with a solenoid coil. The active species were evaluated in terms of the 1st negative system and 2 nd positive system of nitrogen, Ar I (4p'-4s') and Ar II (4p-4s) by optical emission spectroscopy.

The temporal behavior of the electron energy distribution function and plasma parameters in the vicinity of the substrate have been investigated in detail by performing time-resolved probe measurements in a pulsed and unbalanced magnetron argon discharge. A 20-kHz midfrequency unipolar dc pulse with an on-time average power of 160W and a duty cycle of 50% was applied to the metallic cathode target. It was found that the high-energy electrons with energies higher than the sheath potential energy are generated within a few microseconds after the dc pulse is turned on and the electron energy distribution functions during the pulse-on period show a bi-Maxwellian distribution with the high-energy electron group. In the afterglow after the dc pulse is turned off, the initial fast decay of the high-energy electrons and the subsequent diffusive slower decay of the low-energy electrons were observed. This temporal behavior of the electron energy distribution function reflected two-fold decay characteristics of ele...

The time-resolved probe measurements of the plasma parameters and the electron energy distribution function are carried out in a unipolar pulsed dc magnetron argon discharge. The cathode target is driven by the 20kHz midfrequency unipolar dc pulses at three operating modes, such as constant voltage, constant power, and constant current with the duty cycles ranging from 10% to 90%. It is observed that as the duty cycle is reduced, the electron temperature averaged during the pulse-on period rapidly increases irrespective of the operating mode although the average electron density strongly depends on the operating mode. The comparison of the measured electron energy distribution functions shows that the electron heating during the pulse-on period becomes efficient in the pulse operation with short duty cycle, which is closely related to the deep penetration of the high-voltage sheath into the bulk during the pulse-on period.