• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.5
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• pp.504-509
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• 1999

In-situ cleaning and subsequent silicon epitaxial film growth were performed in a load-locked reactor equipped with Hg-grid UV lamp and PBN heater to obtain the smooth and contaminant-free underlying surface and develop low-temperature epitaxial film growth process. The removals of organic and native oxide were investigated using UV-excited $O_2$ and $NF_{3}/H_{2}$, and the effect of the surface condition was examined on the quality of silicon epitaxial film grown at temperature as low as $750^{\circ}C$. UV-excited gas phase cleaning was found to be effective in removing the organic and native oxide successfully providing a smooth surface with RMS roughness of 0.5$\AA$ at optimal condition. Crystalline quality of epitaxial film was determined by smoothness of cleaned surface and the presence of native oxide and impurity. Crystalline defects such as dislocation loops or voids due to the surface roughness were observed by XTEM.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.700-702
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• 2009

We present the epitaxial growth of high-quality ZnO layers by chemical vapor transport (CVT) technique on (01-12) sapphire with a ZnO buffer layer growth by metal-organic chemical vapor deposition (MOCVD). The surface of the grown ZnO epitaxial layers has atomically flats and the RMS is 0.11 nm. PL spectrum of as-grown samples exhibits two emissions originated by interactions between photon and free excitons.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.2
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• pp.125-130
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• 2000

Two step growth of reduced pressure chemical vapor eposition has been successfully developed to achieve in-situ phosphorus-doped silicon epilayers, and the characteristic evolution on their microstructures has been investigated using scanning electron microscopy, transmission electron microscopy, and secondary ion mass spectroscopy. The two step growth, which employs heavily in-situ P doped silicon buffer layer grown at low temperature, proposes crucial advantages in manipulating crystal structures of in-situ phosphorus doped silicon. In particular, our experimental results showed that with annealing of the heavily P doped silicon buffer layers, high-quality epitaxial silicon layers grew on it. the heavily doped phosphorus in buffer layers introduces into native oxide and plays an important role in promoting the dispersion of native oxides. Furthermore, the phosphorus doping concentration remains uniform depth distribution in high quality single crystalline Si films obtained by the two step growth.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.6
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• pp.253-256
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• 2004

Growth of ZnO epitaxial films have been carried out on (0001) sapphire substrates by RF magnetron sputtering. The single crystalline ZnO films of the thickness about 400-500 mm were grown successfully. At the various substrate temperatures of 200～$600^{\circ}C$, the growth behavior and optical properties of the epitaxial films have been characterized. As-grown ZnO films were annealed at the temperatures of 400, 600 and $800^{\circ}C$ respectively in order to characterize the optical properties. The carrier concentration of ZnO films annealed at the temperature of $600^{\circ}C$ was measured $2.6${\times}$10^{16}\textrm{cm}^{-3}$ by Hall measurements.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.361.1-361.1
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• 2014

PbVO3 (PVO), a polar magnetic material considered as a candidate of multiferroic, has ferroelectricity along the c-axis and 2-dimensional antiferromagnetism lying in the in-plane through epitaxial growth [1,2]. PVO thin films were grown on LaAlO3 (001) substrates under reduction atmosphere from a stable Pb2V2O7 sintered target using pulsed laser deposition method. Epitaxial growth of the PVO films is possible only under Ar atmospheren with no oxygen partial pressure. X-ray diffraction was used to investigate the phase formation and texture of the films. We confirmed epitaxial growth of the PVO films with crystalline relationship of PbVO3[001]//LaAlO3[001] and PbVO3[100]//LaAlO3[100]. In addition, surface morphology of the films displays drastic changes in accordance with the growth conditions. Elongated PVO grains are related to the Pb2V2O7 pyrochlore structure. The relation between structural deformation and ferroelectricity in the PVO films was examined by local measurement of piezoresponse force microscopy.

• Transactions on Electrical and Electronic Materials
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• v.1 no.3
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• pp.18-22
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• 2000

In this work, we reported the sulfur compositional variation of ZnS$\_$x/Se$\_$1-x/ epitaxial layers with growth temperature and BEP ration of ZnX/Se/)P$\_$ZnS//P$\_$Se/) grown on GaAs substrates by molecular beam epitaxy. The sulfur composition of ZnSSe epitaxial layers was varied sensitively on the growth temperature and show different linear relationship with growth temperature and BEP ration of ZnS/Se(P$\_$ZnS//P$\_$Se/), which revealed -0.107 %$\^{C}$ at (P$\_$ZnS//P$\_$Se/)=0.30 and -0.052 %$\^{C}$ at (P$\_$ZnS//P$\_$Se/)=0.158 rspectively. A reference data for the accurate control of the sulfur composition and the growth of high quality ZnSSe/GaAs epitaxial layers was provided.

• Journal of the Korean institute of surface engineering
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• v.43 no.4
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• pp.170-175
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• 2010

The GaAs epitaxial layers were grown on Si(100) substrates by molecular beam epitaxy(MBE) using the two-step method. The Si(100) substrates were cleaned with different surface cleaning method of vacuum heating, As-beam, and Ga-beam at the substrate temperature of $800^{\circ}C$. Growth temperature and thickness of the GaAs epitaxial layer were $800^{\circ}C$ and 1 ${\mu}m$, respectively. The surface structure and epitaxial growth were observed by reflection high-energy electron diffraction(RHEED) and scanning electron microscope(SEM). Just surface structure of the Si(100) substrate cleaned by Ga-beam at $800^{\circ}C$ shows double domain ($2{\times}1$). RHEED patterns of the GaAs epitaxial layers grown on Si(100) substrates with cleaning method of vacuum heating, As-beam, and Ga-beam show spot-like, ($2{\times}4$) with spot, and clear ($2{\times}4$). From SEM, it is found that the GaAs epitaxial layers grown on Si(100) substrates with Ga-beam cleaning has a high quality.

• Electrical & Electronic Materials
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• v.16 no.9
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• pp.63.2-64
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• 2003

Epitaxial yttrium-stabilized HfO$_2$ thin films were deposited on p-type (100) Si substrates by pulsed laser deposition at a relatively lower substrate temperature of 550. Transmission electron microscopy observation revealed a fixed orientation relationship between the epitaxial film and Si; that is, (100)Si.(100)HfO$_2$ and [001]Si/[001]HfO$_2$. The film/Si interface is not atomically flat, suggesting possible interfacial reaction and diffusion, X-ray photoelectron spectrum analysis also revealed the interfacial reaction and diffusion evidenced by Hf silicate and Hf-Si bond formation at the interface. The epitaxial growth of the yttrium stabilized HfO$_2$ thin film on bare Si is via a direct growth mechanism without involoving the reaction between Hf atoms and SiO$_2$ layer. High-frequency capacitance-voltage measurement on an as-grown 40-A yttrium-stabilized HfO$_2$ epitaxial film yielded an dielectric constant of about 14 and equivalent oxide thickness to SiO$_2$ of 12 A. The leakage current density is 7.0${\times}$ 10e-2 A/$\textrm{cm}^2$ at 1V gate bias voltage.

• Progress in Superconductivity
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• v.7 no.2
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• pp.120-129
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• 2006

We comparatively studied the epitaxial growth conditions of $CeO_2$ and $Y_2O_3$ thin buffers on textured Ni tapes using rf magnetron sputtering and investigated the feasibility of getting a single mixture layer or sequential layers of $CeO_2$ and $Y_2O_3$ for more simplified buffer architecture. All the buffer layers were first deposited using the reducing gas of $Ar/4%H_2$ and subsequently the reactive gas mixture of Ar and $O_2$, The crystalline quality and biaxial alignment of the films were investigated using X-ray diffraction techniques (${\Theta}-2{\Theta},\;{\phi}\;and\;{\omega}\;scans$, pole figures). The $CeO_2$ single layer exhibited well developed (200) epitaxial growth at the condition of $10%\;O_2$ below an $450^{\circ}C$, but the epitaxial property was decreased with increasing the layer thickness. $Y_2O_3$ seldom showed optimum condition for (400) epitaxial growth. The sequential architecture of $CeO_2/Y_2O_3/CeO_2$ having good epitaxial property was achieved by sputtering at a temperature of $700^{\circ}C$ on the initial $CeO_2$ bottom layer sputtered at $400^{\circ}C$. Cracking of the sputtered buffer layers was seldom observed except the double layer structure of $CeO_2/Y_2O_3$.

• Current Photovoltaic Research
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• v.2 no.1
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• pp.1-7
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• 2014

We developed a method of growing thin Si film at $600^{\circ}C$ by hot wire CVD using a very thin large-grained poly-Si seed layer for thin-film Si solar cells. The seed layer was prepared by crystallizing an amorphous Si film by vapor-induced crystallization using $AlCl_3$ vapor. The average grain size of the p-type epitaxial Si layer was about $20{\mu}m$ and crystallographic defects in the epitaxial layer were mainly low-angle grain boundaries and coincident-site lattice boundaries, which are special boundaries with less electrical activity. Moreover, with a decreasing in-situ boron doping time, the mis-orientation angle between grain boundaries and in-grain defects in epitaxial Si decreased. Due to fewer defects, the epitaxial Si film was high quality evidenced from Raman and TEM analysis. The highest mobility of $360cm^2/V{\cdot}s$ was achieved by decreasing the in-situ boron doping time. The performance of our preliminary thin-film solar cells with a single-side HIT structure and $CoSi_2$ back contact was poor. However, the result showed that the epitaxial Si film has considerable potential for improved performance with a reduced boron doping concentration.