• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.662-665
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• 2002

The growth of carbon nanotubes (CNTs) was carried out using ratio frequency plasma enhanced chemical vapor deposition (rf PECVD) system equipped with dc bias for the directional growth. Acetylene and ammonia gas were used as the carbon source and a catalyst. The relation between gas flow rate and dc bias on the growth of CNTs was investigated. We studied the relation between emission properties and the directionality of CNTs grown under different dc bias voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.247-250
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• 2001

We studied optical properties of SiON thin-film in the applications of optical waveguide. SiON thin-film was grown in $300^{\circ}C$ by PECVD(plasma enhanced chemical vapor deposition) system. The change of SiON thin-film composition and refractive Index was studied as a function of varying $NH_3$ gas flow rate. As $NH_3$ gas flow rate was increased, Quantity of N and refractive index were increased at the same time. By the results, we could form the SiON thin-film to use of a waveguide with refractive index of 1.6. We analyzed the conditions of the thin-film with FTIR(fourier transform infrared) and OES (optical emission spectroscopy). N-H bonding($3390cm^{-1}$ ) can be removed by thermal annealing. And we could observe the SiH bonding state and quantity by OES analysis in $SiH_4$

• Journal of Korean Vacuum Science & Technology
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• v.4 no.2
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• pp.55-60
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• 2000

Vertically aligned carbon nanotubes on nickel coated glass substrates were obtained at low temperatures below 600$\^{C}$ by plasma enhanced hot filament chemical vapor deposition where acetylene gas was used as the carbon source and ammonia gas was used as the dilution gas and catalyst. The diameters of the nanotubes decreased from 96 m to 41 m as NH$_3$/C$_2$H$_2$ ratio increased from 2:1 to 5:1. Total flow rate of input gases with constant NH$_3$/C$_2$H$_2$ ratio did not change the diameter of carbon nanotubes. No growth of the carbon nanotubes was observed with only C$_2$H$_2$ nor N$_2$ instead of NH$_2$. G line and D line in Raman spectra were observed, which implies that there were many structural defects in carbon nanotubes.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.121-122
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• 2011

광도파로 기반 센서의 성능을 개선시키기 위해서는 코어와 클래딩 층의 굴절률 차를 크게 하여 표면감도를 향상시켜야 한다. 이를 위해 센서용 광도파로 코어 층을 위한 고굴절률 SiNx 박막을 플라즈마 화학기상증착(PECVD, plasma enhanced chemical vapor deposition)법을 이용하여 성장한 후 그 표면특성을 분석하였다. 이 때 플라즈마 화학기상증착 공정 조건 중 NH3 가스를 제외하여 Si 성분이 많은 고굴절률 SiNx 박막의 성장을 유도하고 He/SiH4 가스유량비를 0에서 100까지 변화시켜 SiNx 박막의 표면거칠기를 제어하였다. Si기판 위에 SiNx 박막을 10분 성장 후 BOE(buffered oxide etchant)로 선택식각하여 그 박막두께를 alpha step으로 측정하는 방법으로 He/SiH4 가스유량비 조건별 박막성장률을 계산하였다. 그 결과 He/SiH4 가스유량비 증가함에 따라 박막성장률이 33 nm/min에서 19 nm/min으로 선형적인 감소함을 알 수 있었다. 박막두께가 190 nm가 되도록 He/SiH4 가스유량비 조건별 SiNx 박막을 성장한 후 그 표면특성을 AFM (atomic force microscope)으로 관찰하였다. 이를 통해 He/SiH4 가스유량비가 50일 때 SiNx 박막의 표면거칠기가 최소가 됨을 알 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.231-234
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• 2000

Vertically aligned carbon nanotubes were synthesized on Ni-coated Si substrates using microwave plasma-enhanced chemical vapor deposition. The grain size of Ni thin films was varied with the RF power density during the RF magnetron sputtering process. It was found that the diameter, growth rate, and density of carbon nanotubes could be controlled systematically by the grain size of Ni thin films. With decreasing the grain size of Ni thin films, the diameter of the nanotubes decreased, whereas the growth rate and density increased. High-resolution transmission electron microscope images clearly demonstrated synthesized nanotubes to be multiwalled. The number of graphitized wall decreased with decreasing the diameter. Field emission properties will be further presented.

• Transactions on Electrical and Electronic Materials
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• v.7 no.6
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• pp.293-296
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• 2006

We studied homeotropic alignment effect for a nematic liquid crystal (NLC) on the $SiO_{x}$ thin film irradiated by the new ion beam method. $SiO_{x}$ thin films were deposited by plasma enhanced chemical vapor deposition (PECVD) and were treated by the DuoPIGatron ion source. A uniform liquid crystal alignment effect was achieved over 2100 eV ion beam energy. Tilt angle were about $90^{\circ}$ and were not affected by various ion beam energy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.247-250
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• 2001

We studied optical properties of SiON thin-film in the applications of optical waveguide. SiON thin-film was grown in 300$^{\circ}C$ by PECVD(plasma enhanced chemical vapor deposition) system. The change of SiON thin-film composition and refractive Index was studied as a function of varying NH$_3$ gas flow rate. As NH$_3$ gas flow rate was increased, Quantity of N and refractive index were increased at the same time. By the results, we could form the SiON thin-film to use of a waveguide with refractive index of 1.6. We analyzed the conditions of the thin-film with FTIR(fourier transform infrared) and OES(optical emission spectroscopy). N-H bonding(3390cm$\^$-1/) can be removed by thermal annealing. And we could observe the SiH bonding state and quantity by OES analysis in SiH$_4$

• Korean Journal of Materials Research
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• v.29 no.5
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• pp.317-321
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• 2019

We investigated the characteristics of nano crystalline silicon(nc-Si) thin-film solar cells on graphite substrates. Amorphous silicon(a-Si) thin-film solar cells on graphite plates show low conversion efficiency due to high surface roughness, and many recombination by dangling bonds. In previous studies, we deposited barrier films by plasma enhanced chemical vapor deposition(PECVD) on graphite plate to reduce surface roughness and achieved ~7.8 % cell efficiency. In this study, we fabricated nc-Si thin film solar cell on graphite in order to increase the efficiency of solar cells. We achieved 8.45 % efficiency on graphite plate and applied this to nc-Si on graphite sheet for flexible solar cell applications. The characterization of the cell is performed with external quantum efficiency(EQE) and current density-voltage measurements(J-V). As a result, we obtain ~8.42 % cell efficiency in a flexible solar cell fabricated on a graphite sheet, which performance is similar to that of cells fabricated on graphite plates.

• Journal of the Korean Vacuum Society
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• v.1 no.2
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• pp.277-285
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• 1992

플라즈마 화학기상증착법과 저압 화학기상증착법을 사용하여 실리콘 기판 위에 텅 스텐 박막을 증착하였다. 반응기체로 WF6를 사용하였으며 환원기체로는 SiH4를 사용하였다. 플라즈마 증착법에 의한 텅스텐 박막의 성장은 환원기체의 유무에 상관없이 주로 기상 반응 에 의한 텅스텐 덩어리들의 증착에 의하여 이루어졌으며 비교적 균일도가 낮은 박막표면을 이루었다. 저압 화학증착법의 경우 환원기체를 사용하지 않았을 때에는 실리콘 기판에 의한 제한된 환원반응에 의해 텅스텐이 증착되었으나, 환원기체를 사용했을 때에는 초기의 실리 콘 기판에 의한 환원반응과 이어 일어나는 SiH4 기체와의 불균일계 환원반응의 두 단계반응 에 의하여 텅스텐 박막 증착이 이루어졌다. 저압 화학증착법의 경우 텅스텐 박막의 특성은 플라즈마 증착법에서 보다 우수하였으며 박막 성장은 island by island 양식을 따르는 것으 로 추정되었다. 박막은 $\alpha$-W의 체심입방 구조로 이루어졌으며 박막이 성장함에 따라 단결정 구조가 증가하였다.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.64-68
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• 1995

Silicon films were deposited at $430^{\circ}C$ by remote plasma chemical vapor deposition(RPECVD) with a gas mixture of $Si_2H_6/SiF_4/H_2$. The silicon films deposited without and with $SiF_4$ were characterized using atomic force microscopy(AFM), transmission electron microscopy(TEM) and X-ray diffraction(XRD). Both silicon films have the same rugged surface morphology, but, the silicon film deposited with $SiF_4$ exhibits more rugged. The silicon film deposited without $SiF_4$ is amorphous, whereas the silicon film deposited with $SiF_4$ is polycrystalline with very small needle-like grains which are perpendicular to the substrate and uniformly distributed in the thickness of the film. The silicon film deposited with $SiF_4$ was found to have a preferred orientation along the growth direction with the<110> of the film parallel to the <111> of the substrate. The effect of $SiF_4$ during RPECVD was discussed.