• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2333-2337
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• 2007

Nanoporous TiO2 and ZrO2 thin films were spin-coated using a surfactant-templated approach from Pluronic P123 (EO20PO70EO20) as the templating agent, titanium alkoxide (Ti(OC4H9)4) as the inorganic precursor, and butanol as a the solvent. The control of the electronic structure of TiO2 is crucial for its various applications. We found that the band gap of the hybrid nanoporous thin films can be easily tuned by adding an acetylacetonestabilized Zr(OC4H9)4 precursor to the precursor solution of Ti(OC4H9)4. Pores with a diameter of 5 nm-10 nm were randomly dispersed and partially connected to each other inside the films. TiO2 and ZrO2 thin films have an anatase structure and tetragonal structure, respectively, while the TiO2-ZrO2 hybrid film exhibited no crystallinity. The refractive index was significantly changed by varying the atomic ratio of titanium to zirconium. The band gap for the nanoporous TiO2 was estimated to 3.43 eV and that for the TiO2-ZrO2 hybrid film was 3.61 eV.

• Journal of information and communication convergence engineering
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• v.16 no.4
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• pp.248-251
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• 2018

To research the characteristics of $TiO_2$ as an insulator, $TiO_2$ films were prepared with various annealing temperatures. It was researched the currents of $TiO_2$ films with Schottky barriers in accordance with the contact's properties. The potential barrier depends on the Schottky barrier and the current decreases with increasing the potential barrier of $TiO_2$ thin film. The current of $TiO_2$ film annealed at $110^{\circ}C$ was the lowest and the carrier density was decreased and the resistivity was increased with increasing the hall mobility. The Schottky contact is an important factor to become semiconductor device, the potential barrier is proportional to the hall mobility, and the hall mobility increased with increasing the potential barrier and became more insulator properties. The reason of having the high mobility in the thin films in spite of the lowest carrier concentration is that the conduction mechanism in the thin films is due to the band-to-band tunneling phenomenon of electrons.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.3
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• pp.143-148
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• 2009

We have fabricated Ti metal films on Cu wire substrates by using a RF magnetron sputtering method at different RF powers (0, 30 and 60 W) in a high vacuum, and we have investigated the thin film characteristics and resistivity. The ion bombardment effect is increased by the method to superimpose RF power to DC power applied to two poles of the base; thus, the thin film is deposited at sputtering gas pressures below 1 Pa. Moreover, the thin film formation of the multilayer structure becomes possible by gradually injecting the RF power, and the thin film quality is improved.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2002.05a
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• pp.46-46
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• 2002

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 in to the surface of the growing film by bombardment with hyperthermal particles. We were 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 unbalanced magnetron sputter source with attached grid assembly for energetic ion extraction. Also, we have studied the variation of the plasma states by Langmuir probe and Optical Emission Spectroscopy (OES). The epitaxial orientation. microstructual characteristics. electrical and surface properties of the films were analyzed by XRD. SEM. Four point probe and AFM.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.96-101
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• 2011

The thin films of TiN have been used extensively as wear-resistant materials, for instance, such as tools of high-speed cutting, metal mold forming etc. In these days, because the thin films capable of being used more severe conditions are needed, the technologies of arc ion plating are tried to improve its characteristics. The purpose of this study is to investigate the characteristics of thin films of (Ti,Cr)N compared with those of TiN. The method of arc ion plating, which is known as showing good tight-adherence and productivity, was used. After manufacturing thin films of ($Ti_{1-x}Cr_{x}$)N (x=0~1) with change of Cr in (Ti,Cr) target, atomic concentration, structure, size of crystallite, residual stress and surface roughness of thin films on substrate were investigated. As the results, it was confirmed that Cr atomic concentrations of thin films were proportionally changed with Cr atomic concentrations of target, and thin films of ($Ti_{1-x}Cr_{x}$)N (x=0~1) showed NaCl type and CrN existed as solid solution to TiN.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.329-334
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• 2002

This study evaporates TiO$_2$ layer thickness differently with RF sputtering method on Si Wafer(n-100). Thin film is made with the structure of Si+TiO$_2$ and Si+TiO$_2$+Al by evaporating TiN which is used as Antireflection of superintegrated semiconductor integrated circuit with Photo Catalyst. The research is performed to increase the characteristics of photon energy according to TiO$_2$ thickness and the reliability and reproducibility of TiO$_2$ thin film. Reversal of electric Permittivity values is induced by dipole polarization shown in the dielectric of thin film. Complex electric constant ($\varepsilon$$_1$, $\varepsilon$$_2$) has larger peak values as it's thickness is thinner and then it is larger according to the increase of frequency. Electric Permittivity by photon energy has large value in imaginary number and is reduced exponentially by the increase of carrier density according to that of photon energy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.6
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• pp.272-278
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• 2003

$Bi_4Ti_3O_{12}$ (BIT) and $(Bi_{3.25}La_{0.75})(Ti_{2.97}V_{0.03})O_{12}$ (BLTV) thin films were deposited on ITO/glass substrates by metal organic chemical vapor deposition (MOCVD) using ultrasonic spraying. After deposition of the films in oxygen atmosphere for 30 min, the films were heated by rapid thermal annealing (RTA) method, especially direct insertion, at various temperatures. The films were investigated on phase formation temperature, microstructure and electrical properties. From x-ray diffraction (XRD) patterns, the perovskite phase formation temperature of BLTV thin film was about $600^{\circ}C$ which was lower than that of BIT, $650^{\circ}C$. The leakage current of the BLTV thin film was measured to be $1.52\times 10^{-9}$A/$cm^2$ at an applied voltage of 1 V. The remanent polarization (Pr) and coercive field (Ec) values of the BLTV film deposited at $650^{\circ}C$ were $5.6\muC/cm^2$ and 96.5 kV/cm, respectively.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1708-1711
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• 2007

This paper presents high cycle fatigue properties of an Al-3%Ti thin film, used in a RF (radio-frequency) MEMS switch for a mobile phone and also describes new test method for obtaining static and dynamic characteristics of thin film and reliability evaluation method on MEMS device with thin film developed by authors. Durability should be ensured for such devices under cycling load. Therefore, with the proposed specimen and test procedure, tensile and fatigue tests were performed to obtain mechanical and fatigue properties. The specimen was made with dimensions of $1000{\mu}m$ long, $1.0{\mu}m$ thickness, and 3 kinds of width, 50, 100 and $150{\mu}m$. High cycle fatigue tests for each width were also performed, from which the fatigue strength coefficient and the fatigue strength exponent were found to be 193MPa and .0.02319 for $50{\mu}m$, 181MPa and -0.02001 for $100{\mu}m$, and 164MPa and -0.01322 for $150{\mu}m$, respectively. We found that the narrower specimen is, the longer fatigue life of Al-3%Ti is and the wider specimen is, the more susceptible to stress level fatigue life of Al-3%Ti was.

• Journal of Industrial Technology
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• v.25 no.A
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• pp.157-162
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• 2005

In this study, the fabrication of PZT films was performed from a multilayer structure comprising $TiO_2$, $ZrO_2$ and PbO thin films prepared by rapid themal chemical vapor deposition(RTMOCVD). $TiO_2$, $ZrO_2$ and PbO are the component layers of oxide multilayer system for a single phase PZT thin film. The composition control of PZT thin film was done by the thickness control of individual component layer. The composition ratio of Pb:Ti:Zr with thickness were 1:0.94:0.55. Occurrence of a single-phase of PZT was initiated at around $550^{\circ}C$ and almost completed at $750^{\circ}C$ under the fixed time of 1hr. As the concentration of Pb increased, the roughness and crystallization in the film increased. From the as result of using XPS and TEM, the single phase formation through annealing is evident. The electrical properites of the prepared PZT thin film(Zr/Ti=40/60, 300 nm) on a Pt-coated substrate were as follow: dielectric constant ${\varepsilon}_r=475$, coercive field Ec=320 kV/cm, and remanant polarization $P_r=11{\mu}C/cm^2$ at an applied voltage of 18 V.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.9
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• pp.121-127
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• 1994

The capability for application of rf magnetron sputterred and post annealed BaTiO$_{3}$ thin films in dielectrics AC drived TFELD(thin film electroluminescent device) was investigated. The dielectric constant of the thin films slightly increased up to about 25 with increase fothe post annealing temperature in the range of 210$^{\circ}C$-480$^{\circ}C$. The dielectric loss was about 0.005-0.01 except for the high frequency range above 100kHz and nearly independent on post annealing temperature. The BaTiO$_{3}$ thin film used for TFELD was annealed at 480.deg. C and Si$_{3}$N$_{4}$ thin film was inserted between BaTiO$_{3}$, lower dielecrics and ZnS:Mn, phosphor layer for stable driving of the device and for fear of interdiffusion. Regardless of the frequency of the applied sine wave voltage, the threshold voltage of the prepared TFELD was 65volt and saturated brightness was about 3000cd/m$^{2}$ at 130volt(2kHz sine wave), 65volt above V$_{TH}$.