• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.28.1-28.1
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• 2011

We deposited the carbon films on Ni substrates by thermal atomic layer deposition (th-ALD), for the first time, using carbon tetrabromide ($CBr_4$) precursors and H2 reactants at two different temperatures (573 K and 673 K). Morphology of carbon films was characterized by scanning electron microscopy (SEM). The carbon films having amorphous carbon structures were analyzed by X-ray photoemission spectroscopy (XPS) and Raman spectroscopy. As the working temperature was increased from 573 K to 673 K, the intensity of C1s spectra was increased while that of O1s core spectra was reduced. That is, the purity of carbon films containing bromine (Br) atoms was increased. Also, the thin amorphous carbon films (ALD 3 cycle) were transformed to multilayer graphene segregated on Ni layer, through the post-annealing and cooling process.

• Transactions on Electrical and Electronic Materials
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• 제2권3호
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• pp.1-6
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• 2001

A simulation method is proposed to study the amorphous structure of carbon nitride. The material properties of a non-uniform nitrogen distribution in an amorphous CN matrix can be studied. The cohesive energy of a group of randomly generated atoms can be minimized to find the relative positions of atoms. From the calculated configuration of atoms, many properties of amorphous carbon nitride can be calculated such as bulk modulus, P-V curve, sp$^3$/sp$^2$ ratio of carbon, and vibrational spectra. The calculation shows that the cohesive energy of non-uniform nitrogen distribution is lower than that of a uniform distribution. This may suggest that the regular structure of carbon nitride can at most be metastable. It is not easy to incorporate nitrogen atoms into a carbon matrix.

• 반도체디스플레이기술학회지
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• 제4권3호
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• pp.5-9
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• 2005

The bonding structure of organic materials such as fluorinated amorphous carbon films was classified into two types due to the chemical shifts. The electrical properties of fluorinated amorphous carbon films also showed very different effect of two types notwithstanding a very little difference. Fluorinated amorphous carbon films with the cross-link break-age structure existed large leakage current resulting from effect of the electron tunneling. Increasing the cation due to the electron-deficient group increased the barrier height of the films with the cross-link amorphous structure, therefore the electric characteristic of the final materials with low dielectric constant was also improved. The lowest dielectric constant is 2.3 at the sample with the cross-link amorphous structure.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.194-194
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• 2011

The effects of argon neutral beam (NB) energy on the amorphous carbon (a-C) films were investigated, while the a-C films were deposited by neutral particle beam assisted sputtering (NBAS) system. The energy of neutral particle beam can be controlled by reflector bias voltage directly as a unique operating parameter in this system. The deposition characteristics of the films investigated of Raman spectra, UV-visible spectroscopy, electrical conductivity, stress measurement system, and ellipsometer indicate the properties of amorphous carbon films can be manipulated by only NB energy (or reflector bias voltage) without changing any other process parameters. We report the effect of reflector bias voltage in the range from 0 to -1KV. By the increase of the reflector bias voltage, the amount of cross-linked sp2 clusters as well as the sp3 bonding in the a-C film coated by the NBAS system can be increased effectively and the composition of carbon thin films can be changed from nano-crystalline graphite phase to amorphous carbon phase.

• 대한화학회지
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• 제57권6호
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• pp.691-696
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• 2013

Black carbon contributes to global warming and melting of polar ice as well as causing respiratory diseases. However, it is also an inexpensive, easily available carbon nano material for elementary chemistry experiments. In this study, black carbon samples collected from candle light and automobile exhaust pipes have been investigated to examine their compositions and surface characteristics. The observed broad G and D bands and amorphous $sp^3$ band in their Raman spectra as well as the high intensity of the D (defect) band reveal that black carbon is principally made of amorphous graphite. The black carbon deposits in automobile exhaust pipes are apparently more amorphous, probably due to the shorter time allowed for formation of the carbonaceous matter. An exceptionally large water contact angle ($159.7^{\circ}$) is observed on black carbon, confirming its superhydrophobicity. The surface roughness evidently plays an important role for the contact angle much larger than that of crystalline graphite ($98.3^{\circ}$). According to the Sassie-Baxter equation, less than 1% the area actually in contact with the water drop.

• 한국진공학회지
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• 제12권1호
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• pp.25-34
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• 2003

탄소 원자 간의 interaction potential로서 Tersoff에 의해 제안된 반 경험적인 potential을 이용하여 고경질 탄소박막의 합성 거동을 전산 모사하였다. 고에너지의 탄소익사를 diamond (100) 표면에 충돌시켜 고밀도의 비정질 탄소박막을 만들 수 있었으며, 전산모사에 의해 합성된 탄소 박막의 물성과 Shin 등이 발표한 filtered cathodic arc 공정에 의해 합성된 탄소의 물성을 비교하였다. ta-C 합성 실험에서 관찰된 바와 같이 최적의 에너지 영역에서 다이아몬드에 가장 유사한 물성의 필름이 합성되었으며, 이때의 입사원자 에너지인 50 eV 는 실험적으로 최적의 필름이 얻어지는 조건에서의 탄소이온 에너지와 유사하였다. 전산모사에 의해 합성된 박막은 비정질이었으며, 다이아몬드 lattice에 해당하는 short range order를 가지긴 있었다. 그러나, 최적의 에너지 조건에서는 2.1 $\AA$의 거리의 준안정 site에 탄소들이 많이 존재하는 것을 알 수 있었는데, 이는 필름 표면의 국부적 급냉효과가 최대가 되는 조건과 일치하였다. 이러한 결과는 다이아몬드상 카본필름의 합성에 있어서, 고 에너지의 탄소인자가 충돌하면서 발생하는 국소적인 열에너지의 증가가 가장 빨리 제거되는 조건에서 최적의 물성을 가지는 경질탄소 필름이 형성되는 것을 보여주고 있다.

• 전기전자학회논문지
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• 제22권1호
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• pp.213-215
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• 2018

본 연구에서는 실리콘 기판 위에 DC 스퍼터링 방법을 이용하여 비정질 탄소박막을 제작하고, 흡광특성과 광발열 특성을 조사하였다. 비정질 탄소박막은 1000 nm 파장에서 97%의 흡광도를 보였으며, 백색광이 조사됨에 따라 비정질 탄소박막의 온도는 $21.1^{\circ}C$에서 $24.1^{\circ}C$로 상승하여 약 $3^{\circ}C$의 온도가 증가하였다. 또한, 백색광이 50초 동안 조사되는 동안 비정질 탄소박막에서는 기판에 비해 4배 빠른 온도상승속도로 온도가 증가하였다.

• Carbon letters
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• 제4권1호
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• pp.10-13
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• 2003

The structural studies of amorphous isotropic carbon prepared from pyrolysis of phenol formaldehyde resin have been carried out using X-ray diffraction. X-ray diffraction from as prepared sample at $1000^{\circ}C$ and a sample treated at $1900^{\circ}C$ revealed that both are amorphous even though there are small differences in short range order. It is found that both are graphite like carbon (GLC) with predominantly $sp^2$ hybridization. Small angle X-ray scattering results show that as prepared sample mainly consists of thin two dimensional platelets of graphitic carbon whereas they grow in thickness to become three dimensional materials of nano dimensions.

• 한국표면공학회지
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• 제33권2호
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• pp.69-76
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• 2000

The rf plasma chemical vapor deposition is a common method employed for diamond or amorphous carbon deposition. Diamond possesses the strongest bonding, as exemplified by a number of unique properties-extraordinary hardness, high thermal conductivity, and a high melting tempera tore. Therefore, it is very important to investigate the synthesis of semiconducting diamond and its use as semiconductor devices. An inductively coupled rf plasma CVD system for producing amorphous carbon films were developed. Uniform temperature and concentration profiles are requisites for the deposition of high quality large-area films. The system consists of rf matching network, deposition chamber, pumping lines for gas system. Gas mixtures with methane, and hydrogen have been used and Si (100) wafers used as a substrate. Amorphous carbon films were deposited with methane concentration of 1.5% at the process pressure of S torr~20 torr, and process temperature of about $750^{\circ}C$. The nucleation and growth of the amorphous carbon films have been characterized by several methods such as SEM and XRD.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.296-300
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• 2002

Thin films of Hydrogenated amorphous carbon(a-C:H) are generally exhibited by high electrical resistivities from 10$^2$ to 10$\^$16/ Ω$.$cm, resulting in an interesting material for high power, high temperature MIS devices applications. The hydrogenated amorphous carbon(a-C:H) films were deposited on silicon and glass using an rf plasma enhanced CVD method. The resultant film properties were evaluated in the respect of material based on r.f. power variation. The hydrogenated amorphous carbon(a-C:H) films of thickness ranging from 30 to 50 m were deposited at the pressure of 1 ton with the mixture of methane and hydrogen. We have used rf-IR( courier transform IR) and AFM(Atomic force microscopy) for determining physical properties and current-voltage(I-V) measurement for electrical Properties.