• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.8
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• pp.419-422
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• 2001

This paper presents the principle and fabrication of a novel micro mass spectrometer and emission test of hot electron for ionization. A micro mass spectrometer consists of a micro ion source and a micro ion separator. The micro ion source consists of a hot filament and grid electrodes. Electrons emitted from a hot filament are to ionize some sample molecules. The ions are accelerated to an ion detector by an electric field. Mass can be analyzed by using the time of fight depending on the mass-to-charge ratio. The current of hot electron emission from the hot filament is measured for various input voltages.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.585-589
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• 2012

The characteristics of interface layer and the effect of mole fraction of inlet gas mixture($B_2H_6/H_2/N_2/TiCl_4$) on the microstructure of Ti(B,N) films were studied by microwave plasma hot filament CVD process. Ti(B,N) films were deposited on a substrate(STD-61) to develop a high performance of resistance wear coating tool. Ti(B,N) films were obtained at a gas pressure of 1 torr, bias voltage of 300 V and substrate temperature of $480^{\circ}C$ in $B_2H_6/H_2/N_2/TiCl_4$gas system. It was found that TiN, $TiB_2$, TiB and hexagonal boron nitride(h-BN) phases exist in thin layer on the STD-61.

• Journal of the Korean Ceramic Society
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• v.38 no.1
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• pp.34-38
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• 2001

Hot filament CVD 방법에서 가스압을 증가시키는 방법을 사용하여 nanocrystalline 다이아몬드 막을 합성하였다. 메탄-수소 혼합가스를 사용하고 메탄함량, 유량, 기판온도합성시간은 각각 4%, 100sccm, 110$0^{\circ}C$, 10시간으로 일정하게 유 였다. 합성 변수로서 가스압을 40 Torr에서 300 Torr 구간에서 변화시켰다. High-resolution SEM으로 막 표면의 형상을 관찰하고, TEM, XRD, micro-Raman spectroscopy를 사용하여 합성된 막의 구조 및 특성을 분석하였다. 합성된 다이아몬드 막은 압력이 높아짐에 따라 mocrocrystalline 다이아몬드 막에서 점진적으로 nanocrystalline 다이아몬드 막으로 변화해갔으며, 가스압에 다라 비다이아몬드 상의 량이 증가하였다. 증착속도는 microcrystalline 다이아몬드 막이 형성되는 구간에서는 압력에 따라 1.1~1.3 $\mu\textrm{m}$/h까지 증가하다가 nanocrystalline 다이아모느 막이 형성되는 구간에서는 압력에 따라 감소하였다. 감소하였다.

• Journal of the Korean institute of surface engineering
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• v.39 no.3
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• pp.87-92
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• 2006

The characteristic of interface layer and the effect of bias voltage on the microstructure of c-BN films were studied in the microwave plasma hot filament C.V.D process. c-BN films were deposited on a high speed steel(SKH-51) substrate by hot filament CVD technique assisted with a microwave plasma to develop a high performance of resistance coating tool. c-BN films were obtained at a gas pressure of 20 Torr, vias voltage of 300 V and substrate temperature of $800^{\circ}C$ in $B_2H_6-NH_3-H_2$ gas system. It was found that a thin layer of hexagonal boron nitride(h-BN) phase exists at the interface between c-BN layer and substrate.

• Journal of the Korean Ceramic Society
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• v.28 no.10
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• pp.777-784
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• 1991

Diamond films have been growth by the hot-filament chemical vapor deposition (HFCVD) using CH4 and H2 gaseous mixture on the Si substrate. The experimental results indicated that the deposits were pure diamond and contained no amount of non-diamond phases such as amorphous carbon or graphite. The diamond films were deposited well at the conditions: the filament temperature of 210$0^{\circ}C$, the substrate temperature of 77$0^{\circ}C$, the CH4 concentration of 1.76%, the reactor pressure of 30 torr, and the deposition time of 7 hr. At this growth condition, the maximum deposition rate was 2 ${\mu}{\textrm}{m}$/hr. X-ray diffraction patterns and texture coefficient results showed that preferred orientation of the diamond films was {111} orientation under all experimental conditions.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.66-67
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• 2003

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.328-331
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• 2004

Hot filament 플라즈마 화학기상 증착법(HFPECVD)를 사용하여 질산화철의 농도에 따른 탄소나노튜브의 성장 특성을 관찰하기 위해 실험을 진행하였다. 암모니아($NH_3$)를 희석가스로 사용하였고, 아세틸렌($C_2H_2$)를 탄소 원료가스로 각각 사용하였다. 암모니아 가스 플라즈마를 사용하여 전처리 된 질산화철 촉매층의 SEM(Scanning Electron Microscopy) 이미지를 관찰하여 본 결과, 나노 사이즈의 촉매 그레인(grain)을 발견할 수 있었다. 그리고 탄소 나노튜브의 직경과 성장 밀도 또한 전처리 된 촉매 층에 따라 다른 양상을 보였다. TEM(Transmission Electron Microscopy)를 사용하여 탄소나노튜브를 관찰한 결과 bamboo 구조를 한 다중벽 탄소 나노튜브(MWCNT)를 관찰할 수 있었다.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.187-191
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• 2007

In this paper, the catalyst layer is deposited on silicon substrate using magnetron sputtering system and carbon nanotubes(CNTs) were grown in $NH_3\;and\; C_2H_2$ gas by hot-filament plasma enhanced chemical vapor deposition (HFPECVD) system. A growth temperature of carbon nanotubes was changed from $350^{\circ}C\;to\;650^{\circ}C\;by\;100^{\circ}C$. We observed the shape of CNTs by a field-emission scanning electron microscope(FE-SEM) measurement and analyzed the surface characteristic of CNTs layer by contact angle measurement. That is, the growth temperature of CNTs is the important factor leads to the variation of the properties.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.227-232
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• 1998

Diamond crystallization and discontinuous deposit phenomena depend on the process of hydrocarbon deposition, nucleation and growth. Then, it is investigated the concentration of methane, flow rate, structure and the growth process of $CH_4-H_2$ system in hot filament assisted C.V.D. There is a limited value of temperature, pressure, flow rate and the mole fraction of methane-hydrogen gas. Diamond nucleation occurs on substrate selectively and surface diffusion of species on the substrate plays an important role in the early stages of nucleation and growth.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.89-93
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• 2012

c-BN films were deposited on SKH-51 steels by electron assisted hot filament CVD method and microstructure development was studied processing parameters such as bias voltage, temperature, etching and phase transformation at boundary layer between BN compound and steel to develop a high performance wear resistance tools. A negative bias voltage higher than 200V at substrate temperature of $800^{\circ}C$ and gas pressure of 20 torr in B2H6-NH3-H2 gas system was one of optimum conditions to produce c-BN films on the SKH-51 steels. Thin layer of hexagonal boron nitride phase was observed at the interface between c-BN layer and substrate.