• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.09a
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• pp.1-20
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• 1998

Processing of thin films by chemical vapor deposition (CVD) is accompanied by chemical reactions, in which the rigorous kinetic analysis is difficult to achieve. In these conditions, thermodynamic calculation leads to better understanding of the CVD process and helps to optimise the experimental parameters to obtain a desired product. A CVD phase diagram has been used as guide lines for the process. By determining the effect of each process variable on the driving force for deposition, the thermodynamic limit for the substrate temperature that diamond can deposit is calculated in the C-H system by assuming that the limit is defined by the CVD diamond phase diagram. The addition of iso-supersaturation ratio lines to the CVD phase diagram in the Si-Cl-H system provides additional information about the effects of CVD process variables.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.2056-2060
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• 2007

A successful combination of “oxygen-assisted chemical vapor deposition (CVD) process” and Co catalyst nanoparticles to grow highly pure single walled carbon nanotubes (SWNTs) was demonstrated. Recently, it was reported that addition of small amounts of oxygen during CVD process dramatically increased the purity and yield of carbon nanotubes. However, this strategy could not be applied for discrete Fe nanoparticle catalysts from which appropriate yields of SWNTs could be grown directly on solid substrates, and fabricated into field effect transistors (FETs) quite efficiently. The main reason for this failure is due to the carbothermal reduction which results in SiO2 nanotrench formation. We found that the oxygen-assisted CVD process could be successfully applied for the growth of highly pure SWNTs by switching the catalyst from Fe to Co nanoparticles. The topological morphologies and p-type transistor electrical transport properties of the grown SWNTs were examined by using atomic force microscope (AFM), Raman, and from FET devices fabricated by photolithography.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.6
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• pp.515-518
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• 2008

Organic light emitting diode(OLED) is one of the most promising type of future flat panel display. A linear source is used to deposite organic vapor to a large size OLED substrate. An electric heater which is attached on the side of linear source heats the organic powder for the sublimation. The nozzle of heater, which is attached at the top of the linear source has an optimal temperature. An numerical analysis has been performed to find optimal heater position for the optimal nozzle temperature. A commercial CFD program, FLUENT, is used on the analysis. Two-dimensional and three-dimensional analysis have been performed. The analysis showed that the heater should be attached at the outer side of crucible wall rather than inner side of housing, which was original design. Eighteen milimeter from the top of the linear source was suggested as the optimal position of heater. Improving thermal performance of linear source not only helps the uniformity of organic vapor deposition on the substrate but also increase productibity of vapor deposition process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.297-300
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• 1997

In this study, The PVDF thin film was fabricated on the one method of dry-process the physical vapor deposition method, applied electric field, and evaporation control in $\beta$-PVDF thin film preparation. A study on the electric-field-phase change of PVDF thin film in physical vapor deposition using the polymer deposition apparatus which are manufactured for oneself. In the analysis of Fourier-Transform Infrared spectra, according to increasing of electric field intensity, the 510$cm^{-1}$ / peak and 1273$cm^{-1}$ / peak which are showed in $\beta$-PVDF increase, on the contrary the 530$cm^{-1}$ / peak and 977$cm^{-1}$ / peak which are showed in $\alpha$-PVDF decrease.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.2
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• pp.262-271
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• 1999

A study of aerosol dynamics has been done to obtain axially and radially varying size distributions of particles generated in the Modified Chemical Vapor Deposition process. Heat and mass transfer have also been studied since particle generation and deposition strongly depend on the temperature field in a tube. Bimodal size distributions of particles have been obtained both in the particulate flow and in the deposited particle layer for the first time using the sectional method to solve aerosol dynamics. Variations of geometric mean diameter, geometric standard deviation have been studied for various parameters; flow rates and maximum wall temperature. The comparison between one-dimensional and two-dimensional approaches has also been made.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.108-110
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• 2006

A prediction model of charge concentration of silicon nitride (SiN) thin films was constructed by using neural network and genetic algorithm. SIN films were deposited by plasma enhanced chemical vapor deposition and the deposition process was characterized by means of $2^{6-1}$ fractional factorial experiment. Effect of five training factors on the model prediction performance was optimized by using genetic algorithm. This was examined as a function of the learring rate. The root mean squared error of optimized model was 0.975, which is much smaller than statistical regression model by about 45%. The constructed model can facilitate a Qualitative analysis of parameter effects on the charge concentration.

• Korean Journal of Crystallography
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• v.3 no.1
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• pp.53-66
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• 1992

Extensive research has been perform성 on the property-microstructure-process condition relations of thin films. The various proposed models are mainly based on physical vapor deposition processes. Especially the study on the surface condition of substrates in Zone 1 with low surface mobility has not been sufficient. In this study, therefore, we discussed the mochological changes of TiN films deposited by plusma enhanced chemical vapor deposition process with substrates of different composition and micro-rorghness, and compared it with the Structure Zone Model. We could find out that the growth rate of films increased and micro-grain size decreased with the increase in micro-roughness, but it does not improve the mechanical properties because of many imperfections like voids, micro-cracks, stacking faults, etc. This means that, in these deposition conditions, the increase in shadowing diffect is more effective than the increase in nucleation sites on the growth of films due to the increase in substrate roughness.

• Korean Journal of Materials Research
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• v.26 no.9
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• pp.455-459
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• 2016

The deposition process for the gap-filling of sub-micrometer trenches using DMDMOS, $(CH_3)_2Si(OCH_3)_2$, and $C_xH_yO_z$ by flowable chemical vapor deposition (F-CVD) is presented. We obtained low-k films that possess superior gap-filling properties on trench patterns without voids or delamination. The newly developed technique for the gap-filling of submicrometer features will have a great impact on IMD and STI for the next generation of microelectronic devices. Moreover, this bottom up gap-fill mode is expected to be universal in other chemical vapor deposition systems.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.336-339
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• 2007

The enhanced control of OLED deposition processes by Organic Vapor Phase Deposition $(OVPD^{(R)})$ is discussed. $OVPD^{(R)}$ opens a wide space of process control parameters. It allows the accurate and individual control of deposition layer properties like morphology and precise mixing of multi component layers (co-deposition) in comparison to conventional deposition manufacturing processes like e. g. VTE (vacuum thermal evaporation).

• Journal of the Korean institute of surface engineering
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• v.48 no.3
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• pp.126-130
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• 2015

A high-pressure depletion method using plasma chemical vapor deposition (CVD) is often used to deposit hydrogenated microcrystalline silicon (${\mu}c-Si:H$) films of a low defect density at a high deposition rate. To understand proper deposition conditions of ${\mu}c-Si:H$ films for a high-pressure depletion method, Si films were deposited in a combinatorial way using a multi-hollow discharge plasma CVD method. In this paper the substrate temperature dependence of ${\mu}c-Si:H$ film properties are demonstrated. The higher substrate temperature brings about the higher deposition rate, and the process window of device quality ${\mu}c-Si:H$ films becomes wider until $200^{\circ}C$. This is attributed to competitive reactions between Si etching by H atoms and Si deposition.