• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.6
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• pp.311-316
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• 2002

Two different approaches, namely two-step deposition process and Bias-Enhanced Nucleation (BEN) technique have been examined for deposition of high quality diamond thin film on polycrystalline Ni which has low chemical activity with the carbon neutrals provided from the $CH_4/H_2$mixtures. A two-step deposition process, consisted of pre-deposition of soot layer at lower temperatures and subsequent deposition at higher temperature condition, has been developed to deposit diamond layer directly on Ni substrate. Diamond particles were observed after deposition step at $925^{\circ}C$ for 5 hours and those particles seem to be nucleated from the soot layer pre-deposited at lower temperatures ($810^{\circ}C$). Diamond particles of a substantial size were found on Ni substrate after biasing -220 V for 10 minutes and subsequent deposition for 2 hours while no diamond particles were observed under the conditions without applied bias.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.913-914
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• 2006

Amorphous diamond has a very low work function (1 eV) at modest temperature ($150^{\circ}C$). It has been coat coated on electron emitting electrodes. Such electrodes are used for cold cathode fluorescence lamps (CCFL) that illuminate liquid crystal displays (LCD) for rnote books and television sets. Amorphous diamond can dramatically reduce the turn-on voltage to lit CCFL so the lamp life can be greatly extended. Moreover, the electrical current can be increased to enhance the brightness of the light.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.391-394
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• 1999

The diamond thin films are deposited on silicon using MPCVD(Microwave Plasma Chemical Vapor Deposition) method at various deposition microwave power and time. Diamond is deposited with 100 sccm H$_2$ and 2 sccm CH$_4$ by MPCVD. The crystallinity of diamond thin films were increased with increase of microwave power. The growth rate of diamond thin films were increased with increase of time.

• Analytical Science and Technology
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• v.10 no.4
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• pp.1073-1080
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• 1997

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.636-641
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• 2009

Recently, expansion of micro-technology parts requires micro-precision machining technology. Micro-groove machining is important to fabricate micro-grating lens and many micro-parts such as microscope lens, fluidic graphite channel etc. Conventional groove fabrication methods such as etching and lithography have some problems in efficiency and surface integrity. But, mechanical micromachining methods using single crystal diamond tools can reduce these problems in chemical process. For this reason, microfabrication methods are expected to be very efficient, and widely studied. This study deals with machinability in micro-precision V-grooves machining of nickel plated layer using non-rotational single crystal diamond tool and 3-axis micro stages. Micro V-groove shape, chip formation and tool wear were investigated for the analysis of machinability of Ni plated layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.526-529
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• 2002

We studied the nematic liquid crystal (NLC) aligning capabilities by the UV alignment method on a diamond like carbon (DLC) thin film surface. A good LC alignment by UV exposure on the DLC thin film surface at $200\AA$ of layer thickness was achieved. Also, a good LC alignment by the UV alignment method on the DLC thin film surface was observed at annealing temperature of $180^{\circ}C$. However, the alignment defect of the NLC was observed above annealing temperature of $200^{\circ}C$. Consequently, the good thermal stability of LC alignment by the UV alignment method on the DLC thin film surface can be achieved.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 2000.06a
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• pp.87-125
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• 2000

A new paradigm of crystal growth was suggested in a charged cluster model, where charged clusters of nanometer size are suspended in the gas phase in most thin film processes and are a major flux for thin film growth. The existence of these hypothetical clusters was experimentally confirmed in the diamond and silicon CVD processes as well as in gold and tungsten evaporation. These results imply new insights as to the low pressure diamond synthesis without hydrogen, epitaxial growth, selective deposition and fabrication of quantum dots, nanometer-sized powders and nanowires or nanotubes. Based on this concept, we produced such quantum dot structures of carbon, silicon, gold and tungsten. Charged clusters land preferably on conducting substrates over on insulating substrates, resulting in selective deposition. if the behavior of selective deposition is properly controlled, charged clusters can make highly anisotropic growth, leading to nanowires or nanotubes.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.6
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• pp.233-239
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• 2021

In this study, Ga₂O₃/diamond layers were grown on Si substrates to improve the thermal characteristics of Ga₂O₃ materials. Firstly, diamond thin film was grown on Si substrates by hot-filament chemical vapor deposition. Afterward, Ga₂O₃ layer was grown in the growth temperature range of from 450~600℃ by mist chemical vapor deposition. We found that layer separation happens at the Ga₂O₃/diamond interface at the growth temperature of 500℃. This is attributed to the different thermal expansion coefficient of the mixture of amorphous and crystalline structures during cooling process. Therefore, this study might contribute to the heat-sink-layer bonded power semiconductor applications by stabilizing the thermal properties at Ga₂O₃/diamond interface.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.399-400
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.449-450
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• 2008