• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1249-1251
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• 1998

We have studied the properties of $GaAs_{0.35}P_{0.65}$ epitaxial films on the GaP according to doping of $NH_3$ gas using VPE method by CVD. The efficiency of $GaAs_{0.35}P_{0.65}$ epitaxial films found to be greatly enhanced by the according of nitrogen doping. The diodes were fabricated by means of Zn diffusion into vapor grown $GaAs_{0.35}P_{0.65}$ epitaxial films doped with N and Te. The effects of nitrogen doping on carrier density of epitaxial films, PL wavelength and the power out, forward voltage of diodes are discussed. In the end, The effect of electrical and optical properties is influenced by the deep level and deep level density of nitrogen doping.

• Journal of Magnetics
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• 제6권4호
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• pp.129-131
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• 2001

In order to investigate the effect of the interface on GMR, [NiFe(25 ${\AA}$)/Cu(24${\AA}$)]$_2$/Si thin film was epitaxially grown on HF-treated Si (001) substrate using a DC magnetron sputtering method. Typical GMR effects could be observed in epitaxial film with a weak antiferromagnetic exchange coupling while non epitaxial film showed unsaturated and broad MR curves probably due to inter-diffusion between NiFe and Cu layers. Ferromagnetic resonance (FMR) experiment showed two distinct absorption peaks in all films. Each peak was revealed to come from each NiFe layer with different magnetic property. In FMR measurement very clear interface in epitaxial films could be confirmed by a lower value of line width (ΔH) and higher M$\sub$s/ of epitaxial film than those of non epitaxial films, respectively.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.185.2-185.2
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• 2015

Tin Oxide (SnO2) has been widely investigated as a transparent conducting oxide (TCO) and can be used in optoelectronic devices such as solar cell and flat-panel displays. In addition, it would be applicable to fabricating the wide bandgap semiconductor because of its bandgap of 3.6 eV. There have been concentrated on the improvement of optical properties, such as conductivity and transparency, by doping Indium Oxide and Gallium Oxide. Recently, with development of fabrication techniques, high-qulaity SnO2 epitaxial thin films have been studied and received much attention to produce the electronic devices such as sensor and light-emitting diode. In this study, powder sputtering method was employed to deposit epitaxial thin films on sapphire (0001) substrates. A commercial SnO2 powder was sputtered. The samples were prepared with varying the growth parameters such as gas environment and film thickness. Then, the samples were characterized by using XRD, SEM, AFM, and Raman spectroscopy measurements. The details of physical properties of epitaxial SnO2 thin films will be presented.

• The Korean Journal of Ceramics
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• 제6권4호
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• pp.385-389
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• 2000

Residual stresses in epitaxial films were measured by X-ray diffraction method. Lattice strains of the (hkl) planes measured along particular Ψ-angles were converted to the in-plane stress according to the equation of stress-strain tensor conversion. Residual tensile stresses were observed in epitaxial PbTiO$_3$ films deposited on (100) SrTiO$_3$ substrate. Tensile stresses approximately 0.9 GPa were measured in Pb-rich films, while it increased to approximately 2.0 GPa with the decreasing of Pb content in the case of Pb-poor films, which ascribed to the formation of lead and oxygen vacancies (expressed as x in Pb$_1-x$TiO$_3-x$).

• 한국결정성장학회지
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• 제14권6호
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• pp.253-256
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• 2004

단결정상의 ZnO 에피 박막 성장을 사파이어 기판의 (0001)면 상에 RF magnetron sputtering 법으로 수행하였다. 200～$600^{\circ}C$까지의 기판의 온도를 변화하여 가면서 ZnO 에피 박막의 성장 거동을 조사하였으며, 성장된 ZnO 박막에 대하여 산소분위기에서 400, 600, $800^{\circ}C$에서 각각 아닐링을 하여 이에 대한 광 특성을 평가하였다. Hall measurement에 의해 측정 된 carrier concentratin은 $600^{\circ}C$에서 아닐링하여 $2.6${\times}$10^{16}\textrm{cm}^{-3}$이었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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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.

• The Korean Journal of Ceramics
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• 제4권1호
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• pp.33-36
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• 1998

Epitaxially grown $Bi_4Ti_3O_{12}$ thin films on the MgO(100) substrates was prepared by dipping-pyrolysis process using metal naphthenates as starting materials. The films annealed at various temperatures were charactrized by X-ray diffraction $\theta$-2$\theta$ scans and pole-figure analysis ($\beta$ scanning). Highly c-axia oriented Bi4Ti3O12 films were crystallized by heat-treatment at 700$^{\circ}$ and 75$0^{\circ}C$ from precursor films pyrolyzed at 50$0^{\circ}C$. The X-ray pole-figure analysis indicated that the $Bi_4Ti_3O_{12}$ thin films have an epitaxial relationship with the MgO(100) substrates.

• Journal of Magnetics
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• 제13권2호
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• pp.57-60
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• 2008

This study examined the effect of various types of epitaxial strain on the magnetic properties of $SrRuO_3$ thin films. Epitaxial $SrTiO_3$ (001), $SrTiO_3$ (110), and $SrTiO_3$ (111) substrates were used to apply different crystal symmetries to the grown films. The films were grown using pulsed laser deposition. The X-ray diffraction patterns of the films grown under optimum conditions showed very clear peaks for the $SrRuO_3$ film and $SrTiO_3$ substrates. The saturated magnetic moment at 5 K after 7 Tesla field cooling was $1.2-1.4\;{\mu}_B$/Ru. The magnetic easy axis for all three types of films was along the surface normal. The magnetic transition temperature for the $SrRuO_3$ film with lower symmetry was slightly larger than the $SrRuO_3$ film with higher symmetry.

• The Korean Journal of Ceramics
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• 제3권3호
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• pp.191-194
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• 1997

Epitaxial Pb(Zr, Ti)O3(PZT) thin films were prepared on MgO(100) substrates by dipping-pyrolysis (DP) process using metal naphthenates as starting materials, and effects of pyrolysis and final heat-treatment conditions on the film's orientation were investigated. Solid-state epitaxial growth of PZT proceeds at lower temperature around 650℃ from the precursor pyrolyzed at 350 and 500℃. The in-plane alignment of the PZT films depends not only on the final heat-treatment temperature but on the pyrolysis conditions; the films, pyrolyzed at a higher temperature for a short time, i.e., at 500℃ for 10 min, exhibited stronger orientation after the same final heat treatment at 650°∼750℃. The PZT films with the strongest orientation were prepared by pyrolysis under the above conditions followed by final heat treatment at 750℃.

• The Korean Journal of Ceramics
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• 제3권4호
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• pp.253-256
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• 1997

Epitaxially grown Pb(Zr, Ti)O$_3$thin films were prepared on LaAlO$_3$substrates by the dipping pyrolysis process using metal naphthenates as starting materials Homogeneous Pb-Zr-Ti solutions with toluene were spin-coated onto the substrates and pyrolyzed at 50$0^{\circ}C$ Highly oriented Pb(Zr, Ti)O$_3$films confirmed by X-ray diffraction $\theta$-2$\theta$ scans were obtained by heat-treated at 75$0^{\circ}C$ in air The X-ray pole-figure analysis and reciprocal-space mapping of the resulting 0.6$\mu\textrm{m}$ films showed that the thin films comprising the c-axis oriented tetragonal phase have an epitaxial relationship with the LaAlO$_3$substrates.