• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.141-144
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• 2003

This study proposes ZnO thin film as a piezoelectric material for SAW (surface acoustic wave) filter. The ZnO thin film with thickness $2.6{\mu}m$ was deposited (0001)-oriented sapphire by RF magnetron sputtering technique. IDTs (inter-digital transducers) electrodes were patterned upon SAW filter mask with solid finger structure unapodized using lift-off method on ZnO piezoelectric thin film. SAW propagation velocity was measured with the center frequency by HP 8753C network analyzer. A fabricated ZnO SAW filter exhibited a high propagation velocity of 5433 $^m/s$ and relatively insertion loss of -53.391dB at $\lambda=80{\mu}m$. The side-lobe attenuation of the center frequency was about 17dB. When the wavelength was $80{\mu}m$ $(\lambda/4=20{\mu}m)$, the center frequency was 67.907 MHz. $k^2$ (electromechanical coupling coefficient) was 15.84 %.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.1
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• pp.34-42
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• 2001

The influences of substrate temperature were studied when fabricating KLN thin film on amorphous substrate using an rf-magnetron sputtering method. Investigating the vaporization temperature of the each element, the excess ratio of target and the optimum deposition conditions were effectively selected when thin filmizing a material which have elements with large difference fo vaporization temperature. In order to compensate K and Li which have lower vaporization temperatures than Nb, KLN target of composition excess with K of 60% and Li of 30% was used. KLN thin film fabricated on Corning 1737 glass substrate had single KLN phase above 58$0^{\circ}C$ of substrate temperature and crystallized to c-axis direction. The optimum conditions were rf power of 100W, process pressure of 150mTorr, and substrate temperature of $600^{\circ}C$.

• Electrical & Electronic Materials
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• v.10 no.9
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• pp.869-875
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• 1997

Bi based superconducting thin films were fabricated by 4-target RF magnetron sputtering using the method of controlling the on-off time. These thin films showed better crystal structures. The ratio of Cu/Bi decreased but the critical temperature increased with increasing the temperature of the substrate. High temperature phase low temperature of the substrate. High temperature phase low temperature phase and semiconducting phase can be formed by controlling the on-off time of the shutter respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.822-824
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• 2002

Transparent conducting ZnO:$Ga_2O_3$ thin films were deposited on glass substrates using rf magnetron sputtering method. The ZnO:$Ga_2O_3$ thin films were highly c-axis oriented normal to the substrates and had smooth surface features. The sheet resistance of the films was 2.8-6.4 ${\Omega}/{\square}$ at the growth temperature ranging from 25 to 30$^{\circ}C$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.2
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• pp.76-80
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• 2008

In this study, we synthesized ATO films using RF magnetron sputtering method consisted of $SnO_2$ target added Sb of 6 wt% and investigated the effect of $O_2$ on structural, electrical, and optical properties of ATO films. As a result, in case of $O_2$/Ar ratio of 0.11, we obtained ATO films exhibit the properties such as the resistivity about $8{\times}10^{-3}[{\Omega}-cm]$, the transmittance of 85.17%, and retile structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.247-247
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• 2009

In this work, Ga-doped ZnO (GZO) thin films for toxic gas sensor application were deposited on low temperature co-fired ceramic (LTCC) substrates, by RF magnetron sputtering method. LTCC is one of promising materials for integration with heater, low cost production and high manufacturing yields than silicon substrate. The LTCC substrates with thickness of $400\;{\mu}m$ were fabricated by laminating 12 greentapes which consist of alumina and glass particle in an organic binder. The GZO thin films deposited on the substrates and were analyzed by X-ray diffraction method (XRD) and field emission scanning electron microscope (FESEM). The films are well crystallized in the hexagonal (wurzite) structure with increasing thickness. The fabricated sensors showed good sensitivity and fast response time to common types of toxic gases (NOx, COx).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.7
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• pp.567-571
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• 2001

We investigated the structural and electrical properties of Ba(Zr$_{x}$Ti$_{1-x}$ )O$_3$(BZT) thin films with a mole fraction of x=0.2 and a thickness of 150 nm. BZT films were prepared on Pt/SiO$_2$/Si substrate with the various substrate temperature by a RF magnetron sputtering system. When the substrate temperature was above 50$0^{\circ}C$, we obtained multi-crystalline BZT films oriented to (110), (111), and (200) directions. As the substrate temperature increases, the films are crystallized and their dielectric constants become high. C-V characteristic curve of the film deposited at high temperature is more sensitive than that of the film deposited at low temperature. The parameters of the BZT film are as follows; the dielectric constants(dissipation factors) at 1 MHz are 95(0.021), 140(0.024), and 240(0.033) deposited at 400, 500, $600^{\circ}C$, respectively; the leakage currents at 666.7 kV/cm are 5.73, 23.5, and 72.8x10$^{-8}$ A/$\textrm{cm}^2$ fo the films deposited at 400, 500, and 600 $^{\circ}C$, respectively; the leakage currents at 666.7kV/cm are 5.73, 23.5, and 72.8x10$^{-8}$ A/$\textrm{cm}^2$ for the films deposited at 400, 500, $600^{\circ}C$, respectively. The BZT film deposited at 40$0^{\circ}C$ shows stable electrical properties, but dielectric constant for application is a little small.ll.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.309-312
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• 2007

Sputter deposition followed by surface treatment was studied using reactive RF plasma as a method for preparing titanium oxide($TiO_{2}$) films on indium tin oxide(ITO) coated glass substrate for dye-sensitized solar cells(DSSCs). Anatase structure $TiO_{2}$ films deposited by reactive RF magnetron sputtering under the conditions of $Ar/O_{2}$(5%) mixtures, RF power of 600W and substrate temperature of $400^{\circ}C$ were surface-treated by inductive coupled plasma(ICP) with $Ar/O_{2}$ mixtures at substrate temperature of $400^{\circ}C$, and thus the films were applied to the DSSCs, The $TiO_{2}$ Films made on these exhibited the BET specific surface area of 95, the pore volume of $0.3cm^{2}$ and the TEM particle size of ${\sim}25$ nm. The DSSCs made of this $TiO_{2}$ material exhibited an energy conversion efficiency of about 2.25% at $100mW/cm^{2}$ light intensity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.6
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• pp.372-375
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• 2017

ZnO thin films were deposited by RF magnetron sputtering and then diffused by using an As source in the ampouletube. Also, the ZnO p-n homojunction was made by using As-doped ZnO thin films, and its properties were analyzed. After the As doping, the surface roughness increased, the crystal quality deteriorated, and the full width at half maximum was increased. The As-doped ZnO thin films showed typical p-type properties, and their resistivity was as low as $2.19{\times}10^{-3}{\Omega}cm$, probably because of the in-diffusion from an external As source and out-diffusion from the GaAs substrate. Also, the ZnO p-n junction displayed the typical rectification properties of a p-n junction. Therefore, the As diffusion method is effective for obtaining ZnO films with p-type properties.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.5
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• pp.410-416
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• 2001

KLN thin films were fabricated on Pt coated Si(100) wafer using an rf-magnetron sputtering method. The grown KLN thin film consists of 4-fold grains. In this experiment, the structure of 4-fold grained thin film was investigated using XRD and SEM measurements. Pt layer was also deposited using the rf-magnetron sputtering method,. XRD measurement showed that he Pt thin film has Gaussian distribution form with strong (111) direction orientation. The KLN thin film has preferred-orientation of (001) direction, and the peak consists of 2 separate peaks; one with broad FWHM and the other with narrow FWHM. The sharp peak is due to single crystal, and combining with Em results, the 4-fold grain consists of singel crystals with c-axis normal to substrate.