• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.99-100
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• 2005

We have grown carbon nanotubes (CNTs) with a microwave plasma chemical vapor deposition (MPECVD) method, which has been regard as one of the most promising candidates for the synthesis of CNTs due to the vertical alignment, the low temperature and the large area growth. We use methane ($CH_4$) and hydrogen ($H_2$) gas for the growth of CNTs. 60 nm thick Ni catalytic layer were deposited on the TiN coated glass substrate by RF magnetron sputtering method. In this work, we report the effects of pressure on the growth of CNTs. We have changed pressure of processing (10 $\sim$ 20 Torr) deposition of CNTs. SEM (Scanning electron microscopy) images show diameter, length and cross section state CNTs.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.351-351
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• 2011

Graphene has drawn great interests because of its distinctive band structure and physical properties[1]. A few of the practical applications envisioned for graphene include semiconductor applications, optoelectronics (sola cell, touch screens, liquid crystal displays), and graphene based batteries/super-capacitors [2-3]. Recent work has shown that excellent electronic properties are exhibited by large-scale ultrathin graphite films, grown by chemical vapor deposition on a polycrystalline metal and transferred to a device-compatible surface[4]. In this paper, we focussed our scope for the understanding the graphene growth at different conditions, which enables to control the growth towards the application aimed. The graphene was grown using chemical vapor deposition (CVD) with methane and hydrogen gas in vacuum furnace system. The grown graphene was characterized using a scanning electron microscope(SEM) and Raman spectroscopy. We changed the growth temperature from 900 to $1050^{\circ}C$ with various gas flow rate and composition rate. The growth condition for larger domain will be discussed.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.533-537
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• 2007

This paper describes the heteroepitaxial growth of single-crystalline 3C-SiC (cubic silicon carbide) thin films on Si (100) wafers by atmospheric pressure chemical vapor deposition (APCVD) at 1350 oC for micro/nanoelectromechanical system (M/NEMS) applications, in which hexamethyldisilane (HMDS, Si2(CH3)6) was used as a safe organosilane single-source precursor. The HMDS flow rate was 0.5 sccm and the H2 carrier gas flow rate was 2.5 slm. The HMDS flow rate was important in obtaing a mirror-like crystalline surface. The growth rate of the 3C-SiC film in this work was 4.3 μm/h. A 3C-SiC epitaxial film grown on the Si (100) substrate was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Raman scattering, respectively. These results show that the main chemical components of the grown film were single-crystalline 3C-SiC layers. The 3C-SiC film had a very good crystal quality without twins, defects or dislocations, and a very low residual stress.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.36-37
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• 2006

Both negative and positive substrate bias effects on the structural properties and field-emission characteristics are investigated. carbon nanotubes (CNTs) are grown on Ni catalysts employing an inductively-coupled plasma chemical vapor deposition (ICP-CVD) method. Characterization using various techniques, such as field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Auger spectroscopy (AES), and Raman spectroscopy, shows that the physical dimension as well as the crystal quality of CNTs grown can be changed and controlled by the application of substrate bias during CNT growth. It is for the first time observed that the prevailing growth mechanism of CNTs, which is either due to tip-driven growth or based-on-catalyst growth, may be influenced by substrate biasing. It is also seen that negative biasing would be more effectively role in the vertical-alignment of CNTs compared to positive biasing. However, the CNTs grown under the positively bias condition display much better electron emission capabilities than those grown under negative bias or without bias. The reasons for all the measured data regarding the structural properties of CNTs are discussed to confirm the correlation with the observed field-emissive properties.

• Journal of the Semiconductor & Display Technology
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• v.18 no.3
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• pp.115-121
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• 2019

Response surface methodology (RSM) is used to investigate the complex coupling effects of different operating parameters on silicon growth rate in planetary CVD reactor. Based on the computational fluid dynamics (CFD) model, an accurate RSM model is obtained to predict the growth rate with different parameters, including temperature, pressure, rotation speed of the wafer, and the mole fraction of dichlorosilane (DCS). Analysis of variance is used to estimate the contributions of process parameters and their interactions. Among the four operating parameters that have been studied, the influences of susceptor temperature and the operating pressure were the most significant factors that affect silicon growth rate, followed by the mole fraction of DCS. The influence of wafer rotation is the least. The validation tests show that the results of silicon deposition rate obtained from the regression model are in good agreement with those from CFD model and the maximum deviations is 2.15%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.333-334
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• 2007

This paper describes the characteristics of poly (polycrystalline) 3C-SiC grown on SiOz and AlN substrates, respectively. The crystalline quality of poly 3C-SiC was improved from resulting in decrease of FWHM (full width half maximum) of XRD by increasing the growth temperature. The minimum growth temperature of poly 3C-SiC was $1100^{\circ}C$. The surface chemical composition and the electron mobility of poly 3C-SiC grown on each substrate were investigated by XPS and Hall Effect, respectively. The chemical compositions of surface of poly 3C-SiC films grown on $SiO_2$ and AlN were not different. However, their electron mobilities were $7.65\;cm^2/V.s$ and $14.8\;cm^2/V.s$, respectively. Therefore, since the electron mobility of poly 3C-SiC films grown on AlN buffer layer was two times higher than that of 3C-SiC/$SiO_2$, a AlN film is a suitable material, as buffer layer, for the growth of poly 3C-SiC thin films with excellent properties for M/NEMS applications.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.422-448
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• 1996

Low-temperature epitaxial growth of Si and SiGe layers of Si is one of the important processes for the fabrication of the high-speed Si-based heterostructure devices such as heterojunction bipolar transistors. Low-temperature growth ensures the abrupt compositional and doping concentration profiles for future novel devices. Especially in SiGe epitaxy, low-temperature growth is a prerequisite for two-dimensional growth mode for the growth of thin, uniform layers. UHV-ECRCVD is a new growth technique for Si and SiGe epilayers and it is possible to grow epilayers at even lower temperatures than conventional CVD's. SiH and GeH and dopant gases are dissociated by an ECR plasma in an ultrahigh vacuum growth chamber. In situ hydrogen plasma cleaning of the Si native oxide before the epitaxial growth is successfully developed in UHV-ECRCVD. Structural quality of the epilayers are examined by reflection high energy electron diffraction, transmission electron microscopy, Nomarski microscope and atomic force microscope. Device-quality Si and SiGe epilayers are successfully grown at temperatures lower than 600℃ after proper optimization of process parameters such as temperature, total pressure, partial pressures of input gases, plasma power, and substrate dc bias. Dopant incorporation and activation for B in Si and SiGe are studied by secondary ion mass spectrometry and spreading resistance profilometry. Silicon p-n homojunction diodes are fabricated from in situ doped Si layers. I-V characteristics of the diodes shows that the ideality factor is 1.2, implying that the low-temperature silicon epilayers grown by UHV-ECRCVD is truly of device-quality.

• Korean Journal of Materials Research
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• v.14 no.2
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• pp.90-93
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• 2004

Silicon dioxide thin films were deposited on p-type Si (100) substrates by atomic layer deposition (ALD) method using alternating exposures of $SiH_2$$Cl_2$ and $O_3$ at $300^{\circ}C$. $O_3$ was generated by corona discharge inside the delivery line of $O_2$. The oxide film was deposited mainly from $O_3$ not from $O_2$, because the deposited film was not observed without corona discharge under the same process conditions. The growth rate of the deposited films increased linearly with increasing the exposures of $SiH_2$$Cl_2$ and $O_3$ simultaneously, and was saturated at approximately 0.35 nm/cycle with the reactant exposures over $3.6 ${\times}$ 10^{9}$ /L. At a fixed $SiH_2$$Cl_2$ exposure of $1.2 ${\times}$ 10^{9}$L, growth rate increased with $O_3$ exposure and was saturated at approximately 0.28 nm/cycle with $O_3$ exposures over$ 2.4 ${\times}$ 10^{9}$ L. The composition of the deposited film also varied with the exposure of $O_3$. The [O]/[Si] ratio gradually increased up to 2 with increasing the exposure of $O_3$. Finally, the characteristics of ALD films were compared with those of the silicon oxide films deposited by conventional chemical vapor deposition (CVD) methods. The silicon oxide film prepared by ALD at $300^{\circ}C$ showed better stoichiometry and wet etch rate than those of the silicon oxide films deposited by low-pressure CVD (LPCVD) and atmospheric-pressure CVD (APCVD) at the deposition temperatures ranging from 400 to $800^{\circ}C$.

• Korean Journal of Materials Research
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• v.13 no.1
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• pp.1-5
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• 2003

Uniform polycrystalline $CoSi_2$layers have been grown in situ on a polycrystalline Si substrate at temperature near $625^{\circ}C$ by reactive chemical vapor deposition of cyclopentadienyl dicarbonyl cobalt, Co(η$^{5}$ -C$_{5}$ H$_{5}$ )(CO)$_2$. The growth behavior and thermal stability of $CoSi_2$layer grown on polycrystalline Si substrates were investigated. The plate-like CoSi$_2$was initially formed with either (111), (220) or (311) interface on polycrystalline Si substrate. As deposition time was increasing, a uniform epitaxial $CoSi_2$layer was grown from the discrete $CoSi_2$plate, where the orientation of the$ CoSi_2$layer is same as the orientation of polycrystalline Si grain. The interface between $CoSi_2$layer and polycrystalline Si substrate was always (111) coherent. The growth of the uniform $CoSi_2$layer had a parabolic relationship with the deposition time. Therefore we confirmed that the growth of $CoSi_2$layer was controlled by diffusion of cobalt. The thermal stability of $CoSi_2$layer on small grain-sized polycrystalline Si substrate has been investigated using sheet resistance measurement at temperature from $600^{\circ}C$ to $900^{\circ}C$. The $CoSi_2$layer was degraded at $900^{\circ}C$. Inserting a TiN interlayer between polycrystalline Si and $_CoSi2$layers improved the thermal stability of $CoSi_2$layer up to $900^{\circ}C$ due to the suppression of the Co diffusion.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.6
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• pp.290-296
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• 2003

The heteroepitaxial growth of crystalline 3C-SiC on 6H-SiC substrates using high purity silane ($SiH_4$) and prophane ($C_3H^8$) was carried out by thermal chemical vapor deposition, and growth characteristics were investigated in this study. In case that the flow ratio of C/Si and flow rate of $H_2$ were 4.0 and 5.0 slm, respectively, the growth rate of epilayers was about 1.8 $\mu$m/h at growth temperature of $1200^{\circ}C$. The Nomarski surface morphology, X-ray diffraction, Raman spectroscopy, and photoluninescence of grown epilayers were measured to investigate the crystallinity. In this study, the high quality of crystalline 3C-SiC heteropitaxial layers was observed at growth temperature of above $1150^{\circ}C$.