• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.594-597
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• 2002

Silicon Oxynitride(SiON) thick films on p-type silicon(100) wafers have obtained by using plasma-enhanced chemical vapor deposition from SiH$_4$ , N$_2$O and N$_2$. Prism coupler measurements show that the refractive indices of SiON layers range from 1.4620 to 1.5312. A high deposition power of 180 W leads to deposition rates of up to 5.92${\mu}$m/h. The influence of the deposition condition on the chemical composition was investigated using X-ray photoelectron spectroscopy. After deposition of the SiON thick films, the films were annealed at 1050$^{\circ}C$ in a nitrogen atmosphere for 2 h to remove absorption band near 1.5${\mu}$m.

• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.116-119
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• 2010

The etching characteristics of zinc oxide (ZnO) were investigated, including the etch rate and the selectivity of ZnO in a $Cl_2/BCl_3$/Ar plasma. It was found that the ZnO etch rate, the RF power, and the gas pressure showed non-monotonic behaviors with an increasing Cl2 fraction in the $Cl_2/BCl_3$/Ar plasma, a gas mixture of $Cl_2$(3 sccm)/$BCl_3$(16 sccm)/Ar (4 sccm) resulted in a maximum ZnO etch rate of 53 nm/min and a maximum etch selectivity of 0.89 for ZnO/$SiO_2$. We used atomic force microscopy to determine the roughness of the surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the plasmas. Due to the relatively low volatility of the by-products formed during etching with $Cl_2/BCl_3$/Ar plasma, ion bombardment and physical sputtering were required to obtain the high ZnO etch rate. The chemical states of the etched surfaces were investigated using X-ray photoelectron spectroscopy (XPS). This data suggested that the ZnO etch mechanism was due to ion enhanced chemical etching.

• Journal of the Korean Society for Heat Treatment
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• v.14 no.5
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• pp.292-296
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• 2001

In this work, an ultra-high vacuum activated reactive evaporation equipment was built. With reaction of Al and oxygen plasma, $Al_2O_3$ was deposited on the surface of etched Al foil. The chamber was evacuated down to $2{\times}10^{-7}$ torr initially. The Ar and $O_2$ gas introduced into the chamber to maintain $5{\times}10^{-5}$ torr during deposition. Ar gas prevents recombining of the ionized oxygen. Evaporation was maintained by electron beam evaporator continuously. Heating filament and electrode were used in order to generate plasma. The substrate bias of -300V was introduced to accelerate deposition of evaporated Al atoms. The composition and morphology of deposited $Al_2O_3$ films were analyzed by x-ray photoelectron spectroscopy(XPS) and atomic force microscopy (AFM), respectively. The Al oxide was formed on the surface of etched Al foil. According to AFM results, the surface morphology of $Al_2O_3$ film indicates uniform feature. Dielectric characteristic was measured as a function of frequency. Measured withstanding voltage and capacitance were 52V and $24{\mu}F/cm^2$, respectively. The obtained $Al_2O_3$ film shows clean condition without contaminants, which could be adapted to capacitor production.

• Journal of Radiation Industry
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• v.3 no.1
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• pp.1-5
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• 2009

The variation of MgO surfaces, in which fluorine was contained (F-MgO), by high energy electron-beam (EB) was studied using X-ray photoelectron spectroscopy (XPS). Fluorine on the MgO surface was eliminated by EB treatment with the consequence that the electronic structures of Mg, O and C were varied. Moreover, as a result of oxidation of carbon species on the surface by high dose EB treatment (90 kGy), the concentration of carbonate and carboxyl species on the surface was increased. In this experiment, it was confirmed that the structure of oxidized metal surface can be adjusted by varying conditions of EB treatment (energy and dose). This result implies that EB can be applied for developing new catalysts.

• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.190-196
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• 1998

Amorphous ternary $Si_xC_yN-z$ thin films were obtained by plasma enhanced chemical vapor deposition(PECVD) using $N_2, SiH_4 \;and \;C_2H_4$ as the reaction sources. The chemical state were characterized by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy(FTIR). The optical properties of the thin films were investigated by UV-visible spectrophotometer and ellipsometer, and the optical band gaps of thin films were determined from corresponding transmittance spectra following Tauc equation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.7
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• pp.8-16
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• 2010

In this paper, we investigated the effects of $O_2$ fraction on the properties of Al-doped ZnO (AZO) thin films prepared by radio frequency (RF) magnetron sputtering. Hall, photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS) measurements revealed that the p-type conductivity was exhibited for AZO films with an $O_2$ fraction of 0.9 while the n-type conductivity was observed for films with $O_2$ fractions in range of 0 - 0.6. PL and XPS also showed that the acceptor-like defects, such as zinc vacancies and oxygen interstitials, increased in films prepared by an $O_2$ fraction of 0.9, resulting in the p-type conductivity in the films. Hall results indicated that AZO films prepared by $O_2$ fractions in range of 0 - 0.6 can be used for electrode layers in the applications of transparent thin film transistor. We concluded from the X-ray diffraction analysis that worse crystallinity with a smaller grain size as well as higher tensile stress was observed in the films prepared by a higher $O_2$ fraction, which is related to incorporation of more oxygen atoms into the films during deposition. The study of atomic force microscope suggested that the smoother surface morphology was observed in films prepared by using $O_2$ fraction, which causes the higher resistivity in those films, as evidenced by Hall measurements.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.49-49
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• 2009

Nanocomposites of gold nanoparticles and multi-walled carbon nanotubes (MWNTs) were prepared by electrostatic interaction. Gold nanopartic1es were stabilized by polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS) and poly(sodium-4-styrenesulfonate) (PSS) in aqueous medium, and MWNTs were modified by poly(diallyldimethylammonium)chloride (PDDA) in water. The as-perpared Au-MWNT nanocomposites were structurally and electrically characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV/Vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and cyclo voltammetry (CV). UV/Vis spectra of Au-MWNT nanocomposites showed the characteristic surface plasmon bands in the range of ~515nm, depending on the stabilizers. There is only slight change on the band shape with variation of stabilizing agents for gold nanoparticles. Through FE-SEM and TEM images, the distribution of gold, nanoparticles on the sidewalls of MWNTs was deliberately investigated on Au-MWNT nanocomposites treated with different stabilizers. XPS and CV showed redistribution of electron densities and changes in the binding energy states of nanopartic1es in nanocomposite respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2088-2092
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• 2011

The accelerated thermal aging of CSPE(chloro sulfonate polyethylene) of test cables were carried out for the period equal to 10, 20 and 30 years in air at $100^{\circ}C$, respectively. The CSPE cables(TAIHAN electric wire Co. Ltd) which installed in nuclear power plant for three years were used as starting materials. Condition monitering methods of the accelerated thermal aging of CSPE cables were estimated through indenter modulus and OIT(oxidation induction time) of IEC 62582, and those were newly estimated through volume electrical resistivity, ultrasound reflection time, density, FE-SEM(field emission scanning electron microscopy), XPS(x-ray photoelectron spectroscopy), EDS(energy dispersive spectroscopy), and WD-XRF(wavelength dispersive x-ray fluorescence). A new condition monitoring methods of the accelerated thermal aging of CSPE cables were generally coincident with trend of indenter modulus expect EDS, XPS and XRF. A volume electrical resistivity among new condition monitoring methods of the accelerated thermal aging of CSPE cables is excellent. It is considered that life-time of CSPE cable can be predicted through volume electrical resistivity, if CSPE jacket was aged for period such as more than 20 years.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.195-195
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• 2010

$Ga_2O_3$ thin films have been grown on Si(001) substrates by metalorganic chemical vapor deposition (MOCVD) using dimethylgallium isopropoxide ($Me_2GaO^iPr$, DMGIP) with oxygen as the reactant gas. Suitability of the precursor for CVD was confirmed by thermogravimetric analysis (TGA) and vapor pressure measurement. Deposition was carried out in the substrate temperature range $450-650^{\circ}C$. Spectroscopic ellipsometry, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) and Rutherford back-scattering spectroscopy (RBS) were used to determine the thickness, crystallinity, and composition and stoichiometry of the films, respectively. From the slope of the Arrhenius plot in the temperature range $500-550^{\circ}C$, the activation energy of deposition was found to be $225.5\;kJ\;mol^{-1}$. As-deposited films were amorphous, but the monoclinic $\beta-Ga_2O_3$ phase was revealed after annealing the films in air at $1050^{\circ}C$. The XPS and RBS analyses indicate that the $Ga_2O_3$ films obtained by using DMGIP were found to be almost stoichiometric.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.88-88
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• 2010

We synthesized molybdenum thin films deposited by RF magnetron sputtering and physicochemical analysis was performed. The physical and chemical properties of these films were examined with X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The obtained film at the oxygen ratio of 0% showed crystallinity of cubic Mo(110) phase. After the oxygen ratio increased more than 5% in the sputter gas, the molybdenum films were formed as an amorphous phase. The thickness of the Mo thin film was drastically decreased from 1000 nm to ca 70 nm after introduction of oxygen in the sputter gas confirmed by spectroscopic ellipsometer (SE) and scanning electron spectroscopy (SEM). The calculated band gap of the film deduced from SE data increased from 3.17 to 3.63 eV by addition of oxygen in the sputter gas. The roughness of the Mo film was examined with atomic force microscopy (AFM) and it was dramatically decreased by introducing of oxygen during sputtering. XPS results revealed that the ratio of metallic Mo species in the film decreased by the contents of Mo(VI) species increased at the ratio of oxygen increased in the sputter gas and fully oxidized at low content of oxygen in the sputter gas.