• The Korean Journal of Ceramics
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• v.1 no.4
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• pp.204-208
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• 1995

The microstructure and electrical propetries were investigated for polycrystalline $Ba^{1-x}Sr_xTiO_3$(BST) thin films deposited on Pt/Ti/$SiO_2$(PTSS) and Pt/MgO(PM) substrates by metalorganic chemical vapor deposition (MOCVD). BST films on PTSS have coulmnar and porous structures, while on PM have an equiaxied and dense structure. The dielectric constant and a dissipation factor of BST films on PTSS and 20 fC/$\mu \textrm{cm}^3$ on PTSS and 12fC/$\mu \textrm{cm}^2$ on PM was obtained at an applied electric field of 0.06 MV/cm. Leakage current density of BST films on PM was smaller than that on PTSS. The leakage current density level was about $8\times10^{-8}A/\textrm{cm}^2$ at 0.04MV/cm.

• Journal of Photoscience
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• v.7 no.1
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• pp.27-30
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• 2000

The Photoluminescence (PL) measurement results of a very good quality GaN sample grown by metalorganic chemical vapor deposition (MOCVD) are reported. The temperature dependences of peak position, emission intensity, and the full width at half maximum (FWHM) of free-exciton (FX) A and B are presented. Our results show the fast thermal quenching of FX transition intensities and predominantly acoustic phonon scattering of emission line broadening. The transition-energy-shift following the Varshni's empirical equation, and by using it to fit the data, E$\_$A1/(T) = 3.4861 eV -6.046 $\times$ 10$\^$-4/T$^2$ (620.3+ T) eV, E$\_$B1/(T) = 3.4928 eV -4.777 $\times$ 10$\^$-4/T$^2$ / (408.2+ T) eV and E$\_$A2/ = 3.4991 eV -4.426 $\times$ 10$\^$-4/ T$^2$ / (430.6+ T) eV for A(n=1), B(n=1), and A(n=2) are obtained respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.95-95
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• 1997

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.2
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• pp.127-130
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• 2005

The structural and electrical properties of InN/GaN multiple quantum wells, which were grown by metalorganic chemical vapor deposition, were characterized by transmission electron microscopy and electroluminescence measurements. As the quantum well growth time was changed, the wavelength was varied from 451 to 531 nm. In the varied current conditions, the blue LED with the InN MQW structures did not have the wavelength shift. With this result, we can expect that the white LEDs with the InN MQW structures do not show the color temperature changes with the variations of applied currents.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.4
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• pp.33-37
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• 1992

AlGaAs/GaAs quantum well delta-doped channel FET's have been successfully fabricated using by low-pressure metalorganic chemical vapor deposition(LP-MOCVD). The FET's with a gate dimension of 1.8$\mu$m $\times$ 100$\mu$m have a maximum transconductance of 190 mS/mm and a maximum current density of 425 mA/nm. The devices show extremely broad transconductances with a large voltage swing of 2.4V. The S-parameter measurements have indicated that the current gain and power gain cutoff frequencies of the device were 7 and 15 GHz, respectively. These values are among the best performance reported for GaAs based heterojunction FET's with a similar device geometry.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.195-195
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• 2010

$Ga_2O_3$ thin films have been grown on Si(001) substrates by metalorganic chemical vapor deposition (MOCVD) using dimethylgallium isopropoxide ($Me_2GaO^iPr$, DMGIP) with oxygen as the reactant gas. Suitability of the precursor for CVD was confirmed by thermogravimetric analysis (TGA) and vapor pressure measurement. Deposition was carried out in the substrate temperature range $450-650^{\circ}C$. Spectroscopic ellipsometry, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) and Rutherford back-scattering spectroscopy (RBS) were used to determine the thickness, crystallinity, and composition and stoichiometry of the films, respectively. From the slope of the Arrhenius plot in the temperature range $500-550^{\circ}C$, the activation energy of deposition was found to be $225.5\;kJ\;mol^{-1}$. As-deposited films were amorphous, but the monoclinic $\beta-Ga_2O_3$ phase was revealed after annealing the films in air at $1050^{\circ}C$. The XPS and RBS analyses indicate that the $Ga_2O_3$ films obtained by using DMGIP were found to be almost stoichiometric.

• Journal of the Korean Ceramic Society
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• v.34 no.3
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• pp.241-248
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• 1997

RuO2 thin films were deposited on SiO2(1000$\AA$)/Si and MgO(100) single crystal substrates at low tem-peratures by hot-wall metalorganic chemical vapor deposition(MOCVD), and effects of deposition paramet-ers on the properties of the thin films were investigated. RuO2 single phase was obtained at lower de-position temperature of 25$0^{\circ}C$. RuO2 thin films deposited onto SiO2(1000$\AA$)/Si substrates showed a random orientation, and RuO2 films onto MgO(100) single crystals showed the (hk0) orientation. The crystallinity and resistivity of RuO2 thin films increased and decreased with increasing deposition temperature, respec-tively. The resistivity of RuO2 thin films decreased with decreasing the flow rate. The resistivity of the 2600$\AA$-thick RuO2 thin films deposited with O2 flow rate of 50 sccm at 35$0^{\circ}C$ was 52.7$\mu$$\Omega$-cm, and they could be applicable to bottom electrodes of high dielectric materals.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.2020-2021
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• 2004

Distributed optical feedback by gain coupling in V-groove quantum-wire lasers is investigated using InGaAs/AlGaAs active materials grown by metalorganic chemical vapor deposition (MOCVD). In order to avoid grating overgrowth during the fabrication of DFB structures, a newly developed constant MOCVD growth method is employed. Gain anisotropy in emission spectra near Bragg wavelength, resulting from optical feedback along the DFB direction, is clearly observed at room temperature.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.52-55
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• 2003

GaAs/AlGaAs quantum-wire (QWR) gain-coupled distributed-feedback (GC-DFB) lasers are fabricated and characterized Constant metalorganic chemical vapor deposition (MOCVD) growth is used to avoid grating overgrowth during the fabrication of DFB structures. Numerical calculation shows large gain anisotropy by optical feedback along the DFB directions near Bragg wavelength. DFB lasing via QWR active gratings is also experimentally achieved.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.770-775
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• 2001

Numerical calculation has been performed to investigate the fluid flow, heat transfer and local mass fraction of chemical species in the MOCVD (metalorganic chemical vapor deposition) manufacturing process. The mixing of reactants (trimethylgallium with hydrogen gas and ammonia) was presented by the concentration of each reactants to predict the uniformity of film growth. Effects of inlet size, location, mass flow rate and susceptor/cold wall tilt angle on the concentration were reported. The newly developed reactor, that precursors were supplied at separated inlet to prevent from premixing, was investigated to obtain the quantitative verification. As a results, the optimum mass flow rate, wall tilt angle and inlet conditions were proposed.