• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.4
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• pp.481-488
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• 2004

Laser chemical vapor deposition can be used as a new approach for a rapid prototyping technique. The purpose of the study is to fabricate several 3-dimensional objects that are relatively simple as well as to find the characteristics of SiC rod growth that is the first step in developing a new rapid prototyping technique with laser chemical vapor deposition. In the study, SiC rods were generated with varying precursor pressure for 5 minutes. Deposition rates with varying precursor pressure, shapes of rods, surface roughness and component organization were investigated, in particular. Finally, several simple objects like a branch or a propeller were successfully fabricated using laser chemical vapor deposition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.14-21
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• 2005

Laser chemical vapor deposition can be an effective technique for a rapid prototyping with ceramic materials, in particular. The objective of the study is to fabricate several 3-dimensional objects by stacking multi-layers as well as to find out some basic aspects of a rapid prototyping with laser chemical vapor deposition such as deposition characteristics with traversing speed of the laser, possible problems in stacking multi-layers etc. The limit speed of the laser that can grow a tilted SiC rod was found in this study, and laser directing writing that occurs over the limit speed was also investigated. Finally, a zigzag-shaped rod, a spiral-shaped rod, a wall and a square duct were successfully fabricated with laser chemical vapor deposition of tetramethylsilane

• The Korean Journal of Ceramics
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• v.3 no.3
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• pp.177-181
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• 1997

Epitaxial films of cubic silicon carbide (3C-SiC, $\beta$-SiC) have been grown on Si(001) and Si(111) substrates by high vacuum chemical vapor deposition using the single precursor 1,3-disilabutane, $H_3SiCH_2SiH_2CH_3$, at temperatures 900~$100^{\circ}C$. The advantage of using the single precursor over the covnentional chemical vapor deposition is evident in that the source chemical is safe to handle, carbonization of the substrates is not necessary, accurate stoichiometry of the silicon carbide films is easily achieved, and the deposition temperature is much lowered. The films were characterized by XPS, XRD, SEM, RHEED, RBS, AES, and TED.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.9
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• pp.1226-1233
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• 2002

The purpose of the present study was to examine some basic aspects of laser chemical vapor deposition that will be ultimately utilized for solid freeform fabrication of three dimensional objects. Specifically, deposition of silicon carbide (SiC) using tetramethylsilane (TMS) as precursor was studied for a rod grown by $CO_2$laser-assisted chemical vapor deposition. First, temperature distribution for substrate was analyzed to select proper substrate where temperature was high enough for SiC to be deposited. Then, calculations of chemical equilibrium and heat and mass flow with chemical reactions were performed to predict deposition rates, deposit profiles, and deposit components. Finally, several rods were experimentally grown with varying chamber pressure and compared with the theoretical results.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.75-81
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• 2001

MCVD(modified chemical vapor deposition) used in making optical-fiber currently utilizes the hydrogen-oxygen burner as a energy supply source. To improve the productivity and to reduce the manufacturing cost of optical-fiber, a natural gas-oxygen burner has been developed. The manufacturing processes of optical-fiber consist of vapor deposition, collapse and drawing processes. Among these processes, the vapor deposition and the collapse processes are important in terms of improving the productivity and saving the production cost. The vapor deposition and collapse processes are performed by combustion heat and flame force supplied by a burner. So the flame force of the burner used in these processes is required to have an optimal and consistent value in order to allow uniform heating and collapse of quartz tube. In this regard, the momentum ratio of natural gas and oxygen has been optimally determined by modification of a burner and the inlet flow pass also has been modified.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2245-2248
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• 2009

This paper demonstrates room temperature chemical vapor deposition (RTCVD) for fabricating titania inverse opals. The colloidal crystals of monodisperse polymer latex spheres were used as a sacrificial template. Titania was deposited into the interstices between the colloidal spheres by altermate exposures to water and titanium tetrachloride (Ti$Cl_4$) vapors. The deposition was achieved under atmospheric pressure and at room temperature. Titania inverse opals were obtained by burning out the colloidal template at high temperatures. The filling fraction of titania was controlled by the number of deposition of Ti$Cl_4$ vapor. The morphology of inverse opals of titania were investigated. The optical reflection spectra revealed a photonic band gap and was used to estimate the refractive index of titania.

• Journal of the Korean Ceramic Society
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• v.56 no.3
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• pp.277-283
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• 2019

We have examined minimization of the number of impurity particles by replacing the load-lock chamber materials of the chemical vapor deposition equipment through optimization of the pumping method in the deposition chamber. In order to reduce the number of impurity particles in the chamber, the load-lock spacer material was changed from monomer casting nylon to Torlon. Furthermore, we controlled the pumping speed and number of pumping ports, which resulted in a reduction in the impurity particle generation from 2.67% to 0.52%. This study revealed that the selection of the material for the parts of a chemical vapor deposition chamber can minimize particle generation, thereby presenting a method of optimization method of the chemical vapor deposition chamber.

• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.394-399
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• 2000

The effects of the type and thickness of underlayer on the crystallographic texture and the sheet resistance of aluminum thin film were studied. Ti and Ti/TiN were examined as the underlayer of aluminum. Ti and TiN were prepared by ionized physical vapor deposition (I-PVD) metalorganic chemical vapor deposition (MOCVD), respectively. The texture and the sheet resistance of metal thin film stacks were investigated at various thicknesses of Ti or TiN, and the sheet resistance was measured after annealing at $400^{\circ}C$ in an nitrogen ambient. For I-PVD Ti underlayer, the excellent texture of aluminum <111> was obtained even at top of 5 nm of Ti. However, the sheet resistance of the metal stack was greatly increased after annealing due to the interdiffusion and reaction of Al and Ti. MOCVD TiN between Ti and Al could suppress the Al-Ti reaction without severe degradation of aluminum <111> texture. Excellent texture of aluminum was obtained for the MOCVD TiN thinner than 4 nm.

• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1031-1034
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• 1999

Tin oxide films have been grown employing the chemical vapor deposition technique under reduced pressure conditions using tetramethyltin as the precursor and oxygen as the oxidant. An activation energy derived for the deposition reaction under representative deposition conditions has a value of 89±3 kJ mol-1, suggesting a typical kinetic control. Deposition rates of tin oxide films exhibit a near first order dependence on tetramethyltin partial pressure and a zeroth order dependence on oxygen partial pressure. This study provides the first quantitative information about the growth kinetics of tin oxide films from tetramethyltin by the cold-wall low-pressure chemical vapor deposition.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.354-358
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• 1996

High indium incorporation was observed in InGaAs growth by precursor alternating metalorganic chemical vapor deposition (PAMOCVD). A possible mechanism of high indium incorporation into the crystal in PAMOCVD was proposed by considering the decomposition products of gallium and indium precursors, and thus the different adsorption behavior of the decomposed precursor molecules.