• Journal of the Korean Ceramic Society
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• v.54 no.6
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• pp.511-517
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• 2017

With different working pressures and substrate biases, Cr-Al-N coatings were deposited by hybrid physical vapor deposition (PVD) method, consisting of unbalanced magnetron (UBM) sputtering and arc ion plating (AIP) processes. Cr and Al targets were used for the arc ion plating and the sputtering process, respectively. Phase analysis, and composition, binding energy, and microstructural analyses were performed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM), respectively. Surface droplet size of Cr-Al-N coatings was found to decrease with increasing substrate bias. A decrease of the deposition rate of Cr-Al-N films was expected due to the increase of substrate bias. The coatings were grown with textured CrN phase and (111), (200), and (220) planes. X-ray diffraction data show that all Cr-Al-N coatings shifted to lower diffraction angles due to the addition of Al. The XPS results were used to determine the $Cr_2N$, CrN, and (Cr,Al)N binding energies. The compositions of the Cr-Al-N films were measured by XPS to be Cr 23.2~36.9 at%, Al 30.1~40.3 at%, and N 31.3~38.6 at%.

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.331-340
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• 1989

In this study, it was tried to deposit diamond films from a mixture of CH4 and H2 by the microwave plasma chemical vapor deposition(MWCVD). The MWCVD process was designed and set up from the 2.45GHz microwave generator. And the diamond film was successfully deposited on silicon wafers from the mixture of methane and hydrogen. The microstructures of the deposited diamond films were studied by using the following deposition variables : (a) methane concentration(0.6-10%), (b) reaction pressure(10-100torr), and (c) the substrate temperature(450-76$0^{\circ}C$).

• Journal of the Korean Ceramic Society
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• v.48 no.3
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• pp.236-240
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• 2011

In order to deposit a homogeneous and uniform ${\beta}$-SiC films by chemical vapor deposition, we demonstrated the phase stability of ${\beta}$-SiC over graphite and silicon via computational thermodynamic calculation considering pressure, temperature and gas composition as variables. The ${\beta}$-SiC predominant region over other solid phases like carbon and silicon was changed gradually and consistently with temperature and pressure. Practically these maps provide necessary conditions for homogeneous ${\beta}$-SiC deposition of single phase. With the thermodynamic analyses, the CVD apparatus for uniform coating was modeled and simulated with computational fluid dynamics to obtain temperature and flow distribution in the CVD chamber. It gave an inspiration for the uniform temperature distribution and low local flow velocity over the deposition chamber. These calculation and model simulation could provide milestones for improving the thickness uniformity and phase homogeneity.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.2
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• pp.51-56
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• 2022

In this study, we controlled the shape of a carbon layer on gallium oxide templates. Gallium oxide layers were deposited on sapphire substrates using mist chemical vapor deposition. Subsequently, carbon layers were formed using radio frequency plasma chemical vapor deposition. Various shapes of carbon structures appeared according to the fraction of methane gas, used as a precursor. As methane gas concentration was adjusted from 1 to 100%, The shapes of carbon structures varied to diamonds, nanowalls, and spheres. The growth of carbon isotope structures on Ga₂O₃ templates will give rise to improving the electrical and thermal properties in the next-generation electronic applications.

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.323-330
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• 1989

Wear restance titanium carbonitride (TiCN) films were deposited on the SKH9 tool steels and WC-Co cutting tools by plasma assisted chemical vapor deposition (PACVD) using a gaseous mixture of TiCl4, CH4, N2, H2 and Ar. The effects of the deposition temperature and RF(Radio Frequency) power on the deposition rate, chlorine content and crystallinity of the deposited layer were studied. The experimental results showed that the stable and adherent films could be obtained above the deposition temperature of 47$0^{\circ}C$ and maximum deposition rate was obtained at 485$^{\circ}C$. The deposition rate was much affected by RF power and maximum at 40W. The crystallinity of the deposited layer was improved with increasing the deposition temperature and RF power. The TiCN films deposited by PACVD contained much chlorine. The chlorine content in the TiCN films was affected by deposition conditions and decreased with improving the crystallinity of the deposited layer. The deposited TiCN films deposited at the deposition temperature of 52$0^{\circ}C$ and RF power of 40W had an uniform surface with very fine grains of about 500$\AA$ size. The microhardness of the deposited layer was 2,300Kg/$\textrm{mm}^2$.

• Journal of the Korean Ceramic Society
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• v.45 no.7
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• pp.411-417
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• 2008

Aerosol Deposition Method (ADM) is a novel technique to grow ceramic thick films with high density and nano-crystal structure at room temperature. $^{1,2)}$ For these unique advantages of ADM, it would be applied to the fabrication process of 3-D integration ceramic modules effectively. However, it is critical to control the properties of starting powders, because a film formation through ADM is achieved by impaction and consolidation of starting powders on the substrates. We fabricated alumina thick films by ADM for the application to integral substrates for RF modules. When the as-received alumina powders were used as a starting material without any treatments, it was observed that the dielectric properties of as-deposited alumina films, such as relative permittivity and loss tangent, showed high dependency on the frequency. In this study, some techniques of powder pre-treatments to improve the dielectric properties of alumina thick films will be shown and the effects of starting powders on the properties of AD films will be discussed.

• Journal of the Korean Ceramic Society
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• v.31 no.8
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• pp.927-933
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• 1994

Alumina composite membranes were prepared by chemical vapor deposition (CVD) using aluminum-tri-isopropoxide as a precursor. Porous alumina supports were used in deposition, which were in disk shape with mean pore diameter of 0.1 ${\mu}{\textrm}{m}$ and prepared by slip-coasting process. film deposition morphology on porous support was simulated through depositing alumina film on polycrystalline silicon pattern, and its step coverage observed by SEM showed one deviated from uniform step coverage. N2 permeability through composite membranes and the pressure dependence decreased as the deposition time increased. Initially, the N2 permeability of the top layer was tend to decrease rapidly, and then the degree of decrease in N2 permeability was tend to diminish with deposition time. The N2 permeability increased with heat treatment temperature and the crack was generated in top layer at 100$0^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.33 no.4
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• pp.441-447
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• 1996

Sb doped SnO2(ATO:Antinomy doped Tin Oxide) thin films were prepared by a DC magnetron spttuering method using oxide target and the deposition characteristics were investigated. The experimental conditions are as follows :Ar flow rate : 100 sccm oxygen flow rates ; 0-100 sccm deposition temperature ; 250 -40$0^{\circ}C$ DC sputter powder ; 150~550 W and sputtering pressure ; ; 2~7 mTorr. Deposition rate greatly depends not on the deposition temperature but on the reaction pressure oxygen flow rate and sputter power,. when the sputter powder is low ATO thin films with (110) preferred orientation are deposited. And when the sputter power is high (110) prefered orientation appeares with decreasing of oxygen flow rate and increasing of suputte-ring pressure.

• Journal of the Korean Ceramic Society
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• v.30 no.2
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• pp.148-156
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• 1993

TiN films were deposited onto high speed steel (SKH9) by plasma assisted chemical vapor deposition (PACVD) using a TiCl4/N2/H2/Ar gas mixture at around 50$0^{\circ}C$. The effects of the deposition temperature, R.F. power and TiCl4 concentration on the deposition of TiN and the microhardness of TiN film were investigated. The crystallinity and the microhardness of TiN films were improved with increase of the deposition temperature. Optimum deposition temperature in this study was 50$0^{\circ}C$, because a softening or phase transformation of the substrate occurred over 50$0^{\circ}C$. A large increase of the film growth rate with a strong(200) preferred orientation was obtained by increasing R.F. power. Much chlorine content of about 10at.% was found in the deposited films and resulted in relatively low average microhardness of about 1, 500Kgf/$\textrm{mm}^2$ compared with the theoretical value(~2, 000Kgf/$\textrm{mm}^2$).

• Journal of the Korean Ceramic Society
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• v.26 no.1
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• pp.21-30
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• 1989

Titanium Nitride (TiN) was deposited onto the SKH9 tool steels by chemical vapor deposition (CVD) using a gaseous mixture of TiCl4, N2, and H2. The effects of the deposition temperature and input gas composition on the deposition rate, microstructure, preferred orientation, microhardness and wear resistance of TiN deposits were studied. The experimental results showed that the TiN deposition is thermally activated process with an apparent activation energy of about 27Kcal/mole in the temperature range between 1200$^{\circ}$K and 1400$^{\circ}$K. As H2/N2 gas input ratio increased, the deposition rate increased, showed maximum at H2/N2 gas input ratio of 1.5 and then decreased. Mechanical properties such as microhardness and wear resistance have close relation with the microstructure and preferred orientation of TiN deposits. It is suggested that the equiaxed structure with random orientation increases the microhardness and wear resistance of TiN deposits.