• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.1
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• pp.88-92
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• 2010

Bottom gate and top gate field-effect transistor based carbon nanotube(CNT) were fabricated by CMOS process. Carbon nanotube directly grown by thermal chemical vapor deposition(CVD) using Ethylene ($C_2H_4$) gas at $700^{\circ}C$. The growth properties of CNTs on the device were analyzed by SEM and AFM. The electrical transport characteristics of CNT FET were investigated by I-V measurement. Transport through the nanotubes is dominated by holes at room temperature. By varying the gate voltage, bottom gate and top gate field-effect transistor successfully modulated the conductance of FET device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.234-235
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• 2008

The surface flatness of heteroepitaxially grown 3C-SiC thin films is a key factor affecting electronic and mechanical device applications. This paper describes the surface flatness of poly(polycrystalline) 3C-SiC thin films according to Ar flow rates and the geometric structures of reaction tube, respectively. The poly 3C-SiC thin film was deposited by APCVD (Atmospheric pressure chemical vapor deposition) at $1200^{\circ}C$ using HMDS (Hexamethyildisilane : $Si_2(CH_3)_6)$ as single precursor, and 1~10 slm Ar as the main flow gas. According to the increase of main carrier gas, surface fringes and flatness are improved. It shows the distribution of thickness is formed uniformly.

• Journal of the Semiconductor & Display Technology
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• v.3 no.3
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• pp.45-50
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• 2004

Highly oriented diamond (HOD) films in polycrystalline can be grown on the (100) silicon substrate by microwave plasma CVD. Bias enhanced nucleation (BEN) method was adopted for highly oriented diamond deposition with high nucleation density and uniformity. The substrate was biased up to -250[Vdc] and bias time required for forming a diamond film was varied up to 25 minutes. Diamond was deposited by using $\textrm{CH}_4$/CO and $H_2$ mixture gases by microwave plasma CVD. Nucleation density and degree of orientation of the diamond films were studied by SEM. Thermal conductivity of the diamond films was ∼5.27[W/cm.K] measured by $3\omega$ method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.246-249
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• 1997

Diamond thin films were deposited on Si wafer from a mixture of CE$_4$ and H$_2$ by RF Plasma CVD. The films were de77sited under the following conditions : discharge power of 500w, H$_2$ flow rate of 30sccm, chanter pressure of 20∼50Torr, and CH$_4$ concentration of 0.5∼2%. The deposition time was 30∼40 hours because of low growth rate. The deposited films were characterized by Scanning Electron Microscopy and X-ray Diffraction method.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1271-1273
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• 1993

$SiO_2$ and SiON films are formed by Laser CVD for inter-level dielectrics in submicron VLSI. This technique is noticeable that film formation can be done at low temperatures, below $300^{\circ}C$ with less damage. An ArF Excimer Laser with wave length of 193nm is used to excite and dissociate reactant gases. After film formation growth rate, refractive index, I-V curve, and step coverage characteristics of the films were evaluated.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1548-1549
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• 2007

이 실험은 간단한 가열로(heating furnace)를 이용 thermal CVD(chemical Chemical Depositin) 방법을 사용하여, 촉매를 사용하지 않고 실리콘 나노와이어(Si nanowire)를 합성하는 방법에 대해서 연구한 것이다. 굴곡도(roughness)가 큰 알루미나(($Al_{2}O_{3}$) 기판을 사용하여 금(Au)과 같은 촉매를 사용하지 않고 실리콘 나노와이어를 성장시켜 대략 20nm 전후의 지름을 가진 실리콘 나노와이어를 성장시킬 수 있었다. 이 방법은 금을 촉매로 이용하는 방법에 비하여 기판위에 증착되어 성장된 실리콘 나노와이어가 직전성을 가지지 못하고 꼬여있어서 나노와 이어의 분산 과저에서 어려움이 존재하지만 촉매를 사용하지 않기 때문에 성장된 나노와이어에서 촉매를 제거해야하는 어려움을 생략할 수 있고, 기판 위에 촉매를 seeding 하는 작업을 거치지 않고도 20nm 정도의 실리콘 나노와이어를 성장시킬 수 있는 간단한 방법이다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.280-285
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• 1999

$\alpha$-$Fe_2O_3$ thin film gas sensors were deposited at various temperature by CVD method. Polycrystalline $\alpha$-$Fe_2O_3$ thin films were deposited at $175^{\circ}C$ and $200^{\circ}C$. $\gamma$-$\alpha$-$Fe_2O_3$ phase was obtained when the deposition temperature was higher than $250^{\circ}C$. The crystallite size of $\alpha$-$Fe_2O_3$ was affected by the deposition and annealing temperature. The specimen deposited at $175^{\circ}C$ showed maximum sensitivity. In this condition, the sensitivity of $\alpha$-$Fe_2O_3$ thin film for NO gas (at 250 ppm) was 3.2 and response time (at 100ppm) was 12 second.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.232.2-232.2
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• 2014

Since its discovery in 2004, graphene, a sp2-hybridized 2-Dimension carbon material, has drawn enormous attention. A variety of approaches have been attempted, such as epitaxial growth from silicon carbide, chemical reduction of graphene oxide and CVD. Among these approaches, the CVD process takes great attention due to its guarantee of high quality and large scale with high yield on various transition metals. After synthesis of graphene on metal substrate, the subsequent transfer process is needed to transfer graphene onto various target substrates, such as bubbling transfer, renewable epoxy transfer and wet etching transfer. However, those transfer processes are hard to control and inevitably induce defects to graphene film. Especially for wet etching transfer, the metal substrate is totally etched away, which is horrendous resources wasting, time consuming, and unsuitable for industry production. Thus, our group develops one-step process to directly grow graphene on glass substrate in plasma enhanced chemical vapor deposition (PECVD). Copper foil is used as catalyst to enhance the growth of graphene, as well as a temperature shield to provide relatively low temperature to glass substrate. The effect of growth time is reported that longer growth time will provide lower sheet resistance and higher VSG flakes. The VSG with conductivity of $800{\Omega}/sq$ and thickness of 270 nm grown on glass substrate can be obtained under 12 min growing time. The morphology is clearly showed by SEM image and Raman spectra that VSG film is composed of base layer of amorphous carbon and vertically arranged graphene flakes.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.579-579
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• 2012

Graphene has recently been a subject of much interest as a potential platform for future nanodevices such as flexible thin-film transistors, touch panels, and solar cells. And chemical vapor deposition (CVD) and related surface segregation techniques are a potentially scalable approach to synthesizing graphite films on a variety of metal substrates. The structural properties of such films have been studied by a number of methods, including Raman scattering, x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). An understanding of the structural quality and thickness of the graphite films is of paramount importance both in improving growth procedures and understanding the resulting films' electronic properties. In this study, we synthesized the few-layered grapheneunder optimized condition to figure out the growth mechanism seen in CVD-grown graphenee by using various electron microscope. Especially, we observed directly film thickness, quality, nucleation site, and uniformity of grpahene by using AEM. The details will be discussed in my presentation.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.8
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• pp.451-454
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• 2000

We have grown vertically aligned carbon nanotubes in a large area of Co-Ni codeposited Si substrates by the thermal CVD usign $C_2H_2$ gas. Since the discovery of carbon nanotubes, growth of carbon nanotubes has been achieved by several methods such as laser vaporization, arc discharge, and pyrolysis. In particular, growth of vertically aligned nanotubes is important to flat panel display applications. Recently, vertically aligned carbon nanotubes have been grown on glass by PECVD. Aligned carbon nanotubes can be also grown on mesoporous silica and Fe patterned porous silicon using CVD. In this paper, we demonstrate that carbon nanotubes can be vertically aligned on catalyzed Si substrate when the domain density of catalytic particles reaches a certain value. We suggest that steric hindrance between nanotubes at an initial stage of the growth forces nanotubes to align vertically and each nonotubes are grown in bundle.