• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1248-1249
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• 2008

The $V_{1.8}W_{0.2}O_5$ thin films deposited on $Pt/Ti/SiO_2/Si$ substrates by RF sputtering method exhibited fairly good TCR and dielectric properties. It was found that film crystallinity, dielectric properties, and TCR properties were strongly dependent upon the annealing temperature. The dielectric constants of the $V_{1.8}W_{0.2}O_5$ thin films annealed at 400$^{\circ}C$ were 38.11, with a dielectric loss of 0.134, respectively. Also, the TCR values of the $V_{1.8}W_{0.2}O_5$ thin films annealed at 400$^{\circ}C$ were about -3.15%/K.

• Applied Science and Convergence Technology
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• v.23 no.6
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• pp.366-370
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• 2014

ZnO:Al transparent conductive films were deposited on glass substrates by RF magnetron sputtering technique and annealed by rapid thermal annealing system. The influence of annealing time on the structural, electrical, and optical properties of ZnO:Al thin films was investigated by atomic force microscopy, X-ray diffraction, Hall method and optical transmission spectroscopy. As the annealing time increases from 0 to 5 min, the crystallinity is improved, the root main square surface roughness is decreased and the sheet resistance is decreased. The lowest sheet resistance of ZnO:Al thin film is 90 ohm/sq. The reduction of sheet resistance is caused by increasing carrier concentration due to substituent Al ion. All films are transparent up to 80% in the visible wavelength range and the adsorption edge is a blue-shift due to Burstein-Moss effect with increasing annealing time.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.392.1-392.1
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• 2014

Isoindigo based small molecules have attracted much attention in the field of optoelectronic devices due to their broad absorbance and high charge carrier mobilitiies. Herein, we investigate the field effect transistor characteristics of a series of isoindigo based donor-acceptor-donor (D-A-D) small molecules containing a variable number of thiophene moieties (named IDT, ID2T, and ID3T) which form pi-bridges between the D and A moieites and a different donor moiety (IDED). In order to improve the carrier mobility, 1-chloronaphthalene (CN) and 1,8-diiodooctane (DIO) as solvent additives were used. The film morphology, crystallinity and optical properties of the materials processed with various concentrations of solvent additives were investigated through atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-vis absorption spectroscopy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.61-62
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• 2005

The present article deals with in situ post annealing of ZnO in sputtering system. The ZnO thin films were grown at low temperature of $100^{\circ}C$ and at working pressure of 15 mTorr with RF magnetron sputtering. Having been gown, ZnO thin films were annealed in situ at different temperatures, at annealing ambient pressure of 15 mTorr and in ambients of oxygen and argon respectively. Through analyses of XRDs, it is can be concluded that the crystallinity of annealed ZnO thin films becomes much better than that of as-grown ZnO thin film.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.306-306
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• 2011

Three dimensional(3D) topological insulators(TIs) of Bi binary alloys are characterized by a bulk energy gap with strong spin-orbit coupling and metallic surface states protected by time-reversal symmetry. It was reported that film forms of such materials were advantageous over bulk forms due to less defect density and better crystallinity. So far, the films have been prepared on several substrates including semiconductors and graphene. But, there were no studies on metal substrates. For electronic transport experiments and device applications, it is necessary to know epitaxial relation between TIs and metal electrodes. In this study, Atomically flat films of Bi2Se3 were grown on a Au(111) metal substrate by in-situ molecular beam epitaxy. Using home-built scanning tunneling microscope, we observed hexagonal atomic structures which corresponded to the outmost selenium atomic layer of Bi2Se3. Triangular-shaped defects known as Selenium vacancy were also found.

• Laser Solutions
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• v.13 no.1
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• pp.6-10
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• 2010

Crystallization of 100 nm thick amorphous silicon (a-Si) films on glass substrates was carried out by using a double laser irradiation method. Depending on a-Si deposition method or glass types, the quality of crystallized silicon film varies significantly. For a-Si films deposited with high concentration of impurities, large grains or high crystallinity can not be achieved. Crystallization with different a-Si deposition methods confirmed that for the polycrystallization of a-Si films on glass substrates, controlling the impurity density during substrate preparation is critical.

• Journal of the Korean institute of surface engineering
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• v.40 no.3
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• pp.113-116
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• 2007

Titanium dioxide ($TiO_2$) films were deposited by RF reactive magnetron sputtering on non-alkali glass and single crystal MgO (100) substrate at substrate temperature of $400^{\circ}C$. Micro structures of $TiO_2$ films were investigated by XRD, FE-SEM, and Pole figure measurements. $TiO_2$ films deposited on glass substrate showed preferred orientation of anatase (101), whereas $TiO_2$ films deposited on the MgO single crystal substrate showed hetero-epitaxial anatase (100). $TiO_2$ film grown on MgO substrate showed higher photoctalytic activity than that of glass substrate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.82-85
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• 1996

It is considered that the effect of radiation aging, such as electron beam due to the ultra-high voltage for transmission, on the physical properties and electrical characteristics of electrital insulating materials. Low-density polyethylene(thickness 100[${\mu}{\textrm}{m}$]) is selected as an experimental specimen. Fourier transform infra-red spectrum, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy is used so as to analysis the physical properties, the morphological changes and the crystallinity of LDPE. And it is made an experiments of dielectric characteristics in the temperature range of 20[$^{\circ}C$]~120[$^{\circ}C$], in the frequency range of 30[Hz]~1.5$\times$10$^{5}$ [Hz] and in the applied voltage range of 300[mV]~1500[mV].

• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.177-182
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• 1996

strontium titanate (SrTiO3) thin films deposited on Pt/MgO were prepared by Plasma Enhanced Metal Orgainc Chemical vapor Deposition (Pe-MOCVD). The crystallinity of SrTiO3 thin films increased with increasing depo-sition temperature and SrF2 second phase disappeared at 55$0^{\circ}C$ The films showed a dielectric constant of 177 and a dissipation factor of 0.0195 at 100 kHz. The variation of capacitance of the films with applied voltage was small showing paraelectric properties. The charge storage density and leakage current density were 40fC/${\mu}{\textrm}{m}$2 and 3.49$\times$10-7 A/cm2 at 0.25 MV/cm, respectively.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2729-2734
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• 2009

We report here the surface behavior of zirconium oxide deposited on Si(100) substrate depending on the different substrate temperatures. The zirconium oxide thin films were successfully deposited on the Si(100) surfaces applying radio-frequency (RF) magnetron sputtering process. The obtained zirconium oxide films were characterized by X-ray photoelectron spectroscopy (XPS) for study about the chemical environment of the elements, X-ray diffraction (XRD) for check the crystallinity of the films, spectroscopic ellipsometry (SE) technique for measuring the thickness of the films, and the morphology of the films were investigated by atomic force microscope (AFM). We found that the oxidation states of zirconium were changed from zirconium suboxides ($ZrO_{x,y}$, x,y < 2) (x; higher and y; lower oxidation state of zirconium) to zirconia ($ZrO_2$), and the surface was smoothed as the substrate temperature increased.