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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.

Multilayer cubic boron nitride (c-BN) coatings represent a new deposition method that can improve adhesion on metal substrates. The multilayer c-BN system in this study consisted of a TiAlN interlayer (2– 3.5 μm), boron carbide (~ 1 μm), and a c-BN (~ 2 μm) gradient layer. This multilayer c-BN structure, exceeding 5 μm in thickness, showed outstanding adhesion in atmospheric conditions even with high residual stress. Compared to monolayer c-BN coatings, the multilayer c-BN films had lower elastic moduli, and their critical loads were twice as high. The adhesion of the multilayer c-BN system was significantly improved because of the induced stress relaxation.

Cubic boron nitride (c-BN) films on tool substrates are tendency to delaminate. Therefore, many research groups have studied improvement of c-BN synthesis method and deposition processes due to many potential applications. In this paper, we show that the adhesion property of c-BN layer system can be improved by deposing multi c-BN layers. The multi c-BN layers were deposited by r.f (13.56 MHz) diode sputtering apparatus on cemented carbide tool substrates with a TiAlN adhesion layer. For industrial applications, we performed turning and milling experiments under dry and high speed cutting conditions. In this multi c-BN layer system, the lifetime of the tool is affected by the physical properties of the substrate and coated layers such as substrate grain size, thickness of the TiAlN and first c-BN layer and the total number of c-BN layers in this system. Mostly, fine grain size substrates showed longer lifetimes of over 4 times than raw one. In the turning performance, mono TiAlN layer systems were about two times lower lifetime than mono and multi c-BN layer system, moreover, we could be improved adhesion property for milling performance on tool substrates with binary multi c-BN layer systems under dry and high speed cutting conditions. The new application results of the multi c-BN layer system confirm that the high potential of c-BN coatings on cutting tools.

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.

In this work, aluminum doped zinc oxide (AZO) thin films were synthesized at room temperature on PET substrates by using two different types of magnetron sputtering sources at the same time; deposited from two facing ZnO targets in a confined magnetic field, and co-doped from an Al target located outside of this region. The purpose of this system was not only to retain the advantages of the FTS system but also to propose a new type of doping concept. With this configuration, it was expected to get more flexibility for the tuning of Al concentration by controlling the external doping source. For the first, the gas mixture effect on the film properties was studied. In order to get a high quality crystallographic structure for acquiring high mobility, we controlled Ar working pressure, O 2 partial pressure, and H 2 partial pressure in sequence. After deposition, structural, electrical, optical, and surface morphological characteristics were examined. As a result, we could optimize the gas mixture condition including 2.5 mTorr of Ar, 1.2 sccm of O 2 partial pressure, and 3 sccm of H 2 partial pressure. Secondly, Al doping concentration was controlled by changing the external Al target power density. Moderate carrier concentration could be secured by tuning the Al doping. Also, it was deduced that doping reaction might be increased by the Al particles which had moderate energy. As a result, we could deduce the optimized Al power density as 15 W/cm 2 . Under our optimized condition, AZO films could have good electrical and optical properties with a minimum resistivity of 5.344 × 10 − 4 Ωcm and a maximum transmittance of 90.2%. At the end, TCO performance was derived (13.4 mΩ − 1 ) and this value was found to be valuable compared to other authors' latest works and commercial ITO.

Titanium oxide thin films containing silver (Ag) nanoparticles were synthesized on commercially pure titanium (cp-Ti) substrates using a reactive magnetron co-sputtering method. The goal was to maximize bactericidal activity along with sustained biocompatibility. Furthermore, this study examined the correlation between Ag nanoparticle dispersion in the films and the antibacterial efficacy of the Ag ions released from the films. The results showed that there might be two factors affecting the inhibition of bacterial attachment to the surface of the specimens: surface morphology and Ag ion release. MTT assay results demonstrated that there was no cytotoxicity on fibroblast cells in any group. Overall, the magnetron sputtered Ag nanoparticle-containing titanium oxide coatings in this study can be used as an efficient antibacterial layer with sustained biocompatibility.

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.

Transparent lms with low resistivity have been intensively investigated for display device applications, such as at panel displays, solar cells and touch panels, because of their electrodes having low resistivity and high transparency. In this study, the optical and the electrical properties of ITO lms synthesized by using a DC magnetron sputtering system with an ITO (SnO2 : 10 wt.%) target onto a glass, polycarbonate (PC) substrate at various oxygen gas ow rates were investigated and the surface morphologies of ITO thin lms prepared at various lm thicknesses were measured. As a result, ITO thin lms could be prepared with resistivity of 5 8 10 4 -cm and a transmittance of 85 % at a wavelength of 550 nm.

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.

The formation and properties of CrSiN thin films deposited on Si using closed field unbalanced magnetron sputtering system are studied. In this paper, the effect of Si concentration in the CrN films is investigated. Film hardening is generated by the two cases that result from formation of solid solution and formation of nc-CrN/a-Si3N4. Microstructure of the films due to the Si concentration is measured by XRD and TEM. Chemical composition of the films is investigated using GDOES. Also, XPS is analyzed for the examination of the bonding structure of the films. During the AFM, growth mode change from columnar to amorphous is confirmed. Hardness of the film is estimated by nano-indentation test. Maximum hardness value according to the various Si concentration is obtained at 32GPa.

In the downstream region of an unbalanced magnetron argon discharge, the influences of substrate bias (i.e., the condition of plasma boundary) on electron energy distribution function and plasma characteristics were investigated through the experiments using a single Langmuir probe. In a steady state with the grounded substrate, it could be found that the electron current flowing to the substrate compensates for the ion current flowing to the cathode due to the axial magnetic field such that the substrate plays the role of the actual anode. The potential of the anode sheath could be controlled by applying a dc voltage to the substrate, and the nonlinear behavior of the plasma potential with respect to the dc substrate voltage caused the distinctive evolution of the potential of the anode sheath. It was found that a transition of the electron energy distribution function from a bi-Maxwellian distribution at small dc voltages to a Maxwellian distribution at highly negative dc voltages occurs with decreasing...

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.

Surface of a stainless steel has been modified by atmospheric-pressure plasma jet method at room temperature. The impulse voltage is applied to ignite a plasma discharge using high purity (99.999%) reactive gases: N 2 and O 2 . The treated stainless steel is characterized by the activation property of the surface using a contact angle analyzer. Surface energy for the treated stainless steel is increased remarkably when compared to the untreated surface. From the results of X-ray photoelectron spectroscopy and atomic force microscopy, we could confirm that the main functional groups, causing the change in hydrophilic surface were generated under the surface reactions caused by reactive etching and oxidation of ions and activated species in the plasma. In addition, the aging effect during the duration of the hydrophilic property is also studied to investigate the production cost for the industrial applications.

Type 304SS coatings were performed at 200 onto AISI 1045 carbon steel substrate using unbalanced magnetron sputtering (UBMS) with an austenitic AISI 304 stainless steel (SS) target of 100mm diameter. The total deposition pressure in the active Ar gas was 210 Torr. Coatings were done at various target power densities and bias voltages. Chemical compositions of metallic elements of the coatings were measured by energy dispersive X-rays spectroscopy (EDS). The structure and the morphology of Type 304SS coatings were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Corrosion properties of the coated specimens were examined using electrochemical polarization measurements and electrochemical impedance spectroscopy in a deaerated 3.5% NaCl solution. The porosity rate was obtained from a comparison of the dc polarization resistance of the uncoated and coated substrates. Scratch adhesion testing was used to compare the critical loads for different coatings. XRD results showed that the sputtered films exhibit a ferritic b.c.c. -phase. Potentiodynamic polarization curves indicated that all samples had much higher corrosion potential and better corrosion resistance than the bare steel substrate. The corrosion performance increased with increasing power density and the adhesion was enhanced at the bias voltage of -50V. An improvement in the corrosion resistance can be obtained with a better coating adhesion. Finally, an optimized deposition condition for corrosion protection was found as and -50V.

New WC–Ti(1−x)AlxN nanocomposite films were synthesized on Si wafer WC–Co substrate by cathodic arc ion plating. A rotating substrate holder operated at 6 rev./min was used to obtain a layered structure, and the arc power density of Al cathodes was controlled for the change of Al concentration (x) in the film. For the evaluation of crystal structure and compounds formation behavior, X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (XTEM) analyses were performed. The microhardness of WC–Ti(1−x)AlxN films was measured at a normal load of 30 mN by a nano-indentation instrument. WC–Ti0.43Al0.57N nanocomposite film that revealed the highest hardness and good adhesion strength were applied to a printed circuit board (PCB) drill for the evaluation of the drill's lifetime. As a result of adapting a PCB drill coated with WC–Ti0.43Al0.57N film, the lifetime of the PCB drill was improved by more than two times than that of the ordinary one.

We have deposited Hf(C,N) thin films on Si(100) and STD11 steel substrates by pulsed d.c. plasma assisted metal–organic chemical vapor deposition (PA-MOCVD) in the temperature range of 200–300°C. Tetrakis diethylamido hafnium, Hf[N(CH 2 CH 3 ) 2 ] 4 (TDEAH), was used as the hafnium precursor. A mixture of He (90%) and H 2 (10%) in volume ratio was used as the carrier gas, and the N 2 was used as the reactive gas. During CVD, radical formation and ionization behaviors in plasma were analyzed in situ by optical emission spectroscopy (OES) at various pulsed bias voltages and N 2 flow rates. The deposition rate with the change of the flow rate ratio of N 2 reactive gas to He+H 2 carrier gas was also increased to 0.1. With increasing bias voltage, moreover, the film growth rate was continuously increased resulting in carbon-rich films. Highly oriented oxygen-free, polycrystalline Hf(C,N) thin films in the {111} direction were successfully grown on the STD11 steel substrate at 300°C. The hardness of film changed from 1000 to 2500 HK, depending on N 2 gas flow rate ratio and bias voltage. Higher hardness can be obtained for a N 2 gas flow rate ratio of 0.1 and bias voltage of 600 V. The film composition was confirmed with XPS and RBS analysis, and the N 2 reactive gas makes low carbon contents in the films. SEM revealed that surfaces of as-deposited Hf(C,N) thin films were smooth and featureless.

We have deposited Ti(C,N) thin films on Si(100) and D2 steel substrates in the temperature range of 200–300 °C using tetrakis diethylamidotitanium (TDEAT) and titanium isopropoxide (TIP) by pulsed dc plasma-enhanced metalorganic chemical vapor deposition (PEMOCVD). Radical formation and ionization behaviors in plasma are analyzed in situ by optical emission spectroscopy at various pulsed bias voltages and gas conditions. H2 and He+H2 gases are used as carrier gases to compare plasma parameters, and the effect of N2 and NH3 as reactive gas is also evaluated by the reduction of the C content of the films. Polycrystalline Ti(C,N) thin films were successfully grown on either D2 steel or Si(100) surfaces with TDEAT at temperatures as low as 200 °C. For TIP, however, only TiOCN thin films were obtained on Si(100) substrates. The best deposition process is evident for H2 and N2 gas atmospheres and bias voltage of 600 V. The higher film hardness is about 1760 Hk 0.01, but depends on gas species and bias voltage. ...

We have deposited thick SiC thin films on graphite substrates in the temperature range of 700–850 °C using single-molecular precursors by both thermal metal–organic chemical-vapor deposition (MOCVD) and plasma-enhanced MOCVD (PEMOCVD) methods for oxidation-protection wear and tribological coating. Hexamethyldisilane (HMDS), (CH3)3Si–Si(CH3)3, was used as a single-source precursor, and hydrogen and Ar were used as a bubbler and carrier gas. A highly oriented polyerystalline cubic SiC layer in the [111] direction was successfully deposited on graphite at temperatures as low as 800 °C with HMDS by PEMOCVD. For thermal MOCVD, on the other hand, only amorphous SiC layers were obtained at 850 °C. From this study, we confirmed that PEMOCVD was a highly effective process in improving the characteristics of the SiC layers compared to those grown by thermal MOCVD. The mechanical and oxidation-resistant properties have been assessed. The optimum SiC film was obtained at 850 °C and rf power of 200 W. The maximum depo...

The Korea Superconducting Tokamak Advanced Research (KSTAR) Project is the major effort of the Korean National Fusion Program (KNFP) to develop a steady-state-capable advanced superconducting tokamak to establish a scientific and technological basis for an attractive fusion reactor. Major parameters of the tokamak are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 Tesla, and plasma current 2 mA with a strongly shaped plasma cross-section and double-null divertor. The initial pulse length provided by the poloidal magnet system is 20 s, but the pulse length can be increased to 300 s through non-inductive current drive. The plasma heating and current drive system consists of neutral beam, ion cyclotron waves, lower hybrid waves, and electron–cyclotron waves for flexible profile control. A comprehensive set of diagnostics is planned for plasma control and performance evaluation and physics understanding. The project has completed its conceptual design phase and moved to the engineering design phase. The target date of the first plasma is set for year 2002.

ZnO has been studied as a strong candidate for high-quality TCO in accordance with increasing demand to replace ITO. The origin of n-doping in ZnO is not clearly understood, but recently, the H2 effect has received attention due to the role it plays in O-rich and O-poor conditions. In spite of recent rapid developments, controlling the electrical conductivity of ZnO has remained a major challenge. To control the electrical conductivity of ZnO, this study was performed using an FTS system with H2 and O2 addition at low processing temperature. The structural and electrical properties of ZnO thin films deposited at various H2 and O2 flow rates were investigated using XRD and a sheet resistance meter. In response to changes in H2 and O2 flow rates, the crystallization and related grain size of the ZnO films were somewhat changed. The sheet resistance increased from approximately 10(-1) to approximately 10(4) M ohm/sq. when the O2 flow rate was increased, and the resistance decreased from approximately 10(-1) to approximately 10(-4) M ohm/sq. when the H2 flow rate was increased. The increase of sheet resistance with O2 flow rates could be explained by decrease of oxygen vacancies. The decrease of sheet resistance with H2 flow rates could be explained by increase of the electrons from interstitial hydrogen atoms. The plasma characteristics were analyzed using optical emission spectroscopy (OES). But, the overall spectrum did not change with the H2 and O2 gas flow rates. So, the dramatic changes in the electrical properties of ZnO thin films could be considered to be a result of changes in chemical composition of the thin films rather than the plasma status.

To reduce the incidence of postsurgical bacterial infection that may cause implantation failure at the implant-bone interface, surface treatment of titanium implants with antibiotic materials such as silver (Ag) has been proposed. The purpose of this work was to create TiO2 nanotubes using plasma electrolytic oxidation (PEO), followed by formation of an antibacterial Ag nanostructure coating on the TiO2 nanotube layer using a magnetron sputtering system. PEO was performed on commercially pure Ti sheets. The Ag nanostructure was added onto the resulting TiO2 nanotube using magnetron sputtering at varying deposition rates. Field emission scanning electron microscopy and transmission electron microscopy were used to characterize the surface, and Ag content on the TiO2 nanotube layer was analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. Scanning probe microscopy for surface roughness and contact angle measurement were used to indirectly confirm enhanced TiO2 nanotube hydrophilicity. Antibacterial activity of Ag ions in solution was determined by inductively coupled plasma mass spectrometry and antibacterial testing against Staphylococcus aureus (S. aureus). In vitro, TiO2 nanotubes coated with sputtered Ag resulted in significantly reduced S. aureus. Cell viability assays showed no toxicity for the lowest sputtering time group in the osteoblastic cell line MC3T3-E1. These results suggest that a multinanostructured layer with a biocompatible TiO2 nanotube and antimicrobial Ag coating is a promising biomaterial that can be tailored with magnetron sputtering for optimal performance.

Nonthermal atmospheric-pressure plasma discharge is designed with low-temperature cofired ceramic (LTCC) electrodes to achieve dielectric barrier surface discharge (DBSD). The environmental requirement (below 0.05 ppm) of the amount of byproducts (ozone and NO x ) produced during the process was met by optimizing the electrode design to produce a high dielectric barrier discharge for low-voltage (∼700 V) operation and minimizing the distance between electrodes to improve the plasma discharging efficiency. The concentrations of volatile organic compounds (VOCs) within interior cabins of commercial vehicles were significantly reduced after 1-h treatment to improve air quality cost-effectively. This atmospheric-pressure plasma process was demonstrated for the sterilization of Escherichia coli to prevent food poisoning during the preservation of food in refrigerators.

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. Silver-containing titanium oxide (Ag-TiOx) nanocomposite thin films were deposited on cp-Ti substrate using DC reactive magnetron sputtering system. After deposition, heat treatment process was performed under 600°C for 1 hour. It is well known fact that the success of dental implant surgery is dependent on the bone-implant osseointegration. Also, longterm success rate is dependent on the absence of bacteria surrounding the implants which can induce the bio-film formation. In this study, effect of heat treatment on osseointegration and mechanical behavior of the antibacterial sputtered films was investigated.

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. Summary form only given. Polymers frequently replace traditional engineering materials such as metals, glasses and ceramics. The utilization of polymers can further be enhanced by coating them by a protective layers, optical coatings, gas permeation barriers, and others. However, the desirable bulk properties of polymers are often compromised by unfavourable surface characteristics, such as low hardness, low resistance to abrasion and scratching, and low surface energy, that generally leads to poor adhesion. In our previous work, we synthesized Ti-Cu-N and Ti-Ag-N nano-composite films with various Cu and Ag contents. The hardness of Ti-Cu-N and Ti-Ag-N films could be significantly improved by addition of Cu and Ag, indicating that an appropriate amount of doping element was selected. The maximum hardness of these films reached to about 40GPa and friction coefficient was about 0.3 In our study, to overcome the film adhesion problem, we used a pretreatment of a polymer by atmospheric RF plasma After pretreatment, we have deposited Ti-Me-N, nano-composite films on polymer by magnetron sputtering. To analysis of atmospheric plasma and metal doping effect on plasma, we measured plasma states by Optical Emission Spectroscopy (OES) and Residual Gas Analyzer (RGA). The deposition rate, microstructure, surface morphology of the films were studied using /spl alpha/-step profilometer, High Resolution X-Ray Diffraction(HRXRD), Transmission Electron Microscopy(TEM) and Atomic Force Microscope(AFM). The mechanical properties of metal doped transition metal nitride films were evaluated by nano-indentation test.

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.