• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.652-656
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• 2003

The green emitting phosphor, BnGa$_2$O$_4$:Mn thin films with spinel structure were deposited by rf magnetron sputtering at various Ar/O$_2$ ratios. Thin film phosphors were heat-treated in air and $N_2$+vacuum atmosphere, respectively. Effects of Ar/O$_2$ ratios and annealing conditions on the structural and photoluminescence (PL) and cathodeluminescence (CL) properties were investigated. Luminous properties were more improved by inhibiting the films from contacting with oxygen during heat treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.425-428
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• 1999

In this paper, the electrical properties of Pt/YMnO$_3$/Si(100) structures with difference rapid thermal annealing (RTA) treatment were investigated. YMnO$_3$films were obtained without buffer layers, introducing oxygen. A typical value of the dielectric constant was about 20 derived from 1MHz capacitance-voltage (C-V) measurement and the resistivity of the film at the field of 150kV/cm was about 1.34$\times$10$^{12}$ $\Omega$ . cm. The minimum interface state density around midgap was estimated to be about 5$\times$10$^{11}$ cm$^2$. eV.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.54-57
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• 2004

ZnO thin films on (001) sapphire substrates have been deposited by pulsed laser deposition(PLD) technique using an Nd:YAG laser with a wavelength of 266 m. During deposition, the experiment of the deposition of ZnO thin films has been performed for substrate temperatures in the range of $400^{\circ}C$ and flow rate of 350 sccm, films have been annealed at various substrate temperatures after deposition. After post-annealing treatment in the oxygen ambient, the structural properties of ZnO thin films were characterized by diffraction (XRD), SEM and the optical of the ZnO were characterized by photoluminescence (PL).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.205-205
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• 2010

Recently, low temperature co-fired ceramic (LTCC) technology is widely used in sensors, actuators and microsystem fields because of its very good electrical and mechanical properties, high stability as well as possibility of making 3D micro structures. In this study, we investigated the effects of on $O_2$ annealing treatment on the electrical properties of Pb(ZrTi)$O_3$ (PZT) thin films deposited on LTCC substrate. The LTCC substrates with thickness of $400\;{\mu}m$ were fabricated by laminating 4 green tapes which consist of alumina and glass particle in an organic binder. The PZT thin films were deposited on Au / LTCC substrates by RF magnetron sputtering method. The change of the crystallization of the films were investigated under various atmosphere. The structural variation of the films were analyzed by using X-Ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) and secondary ion mass spectrometry (SIMS).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.467-475
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• 2004

ZnO epilayer were synthesized by the pulsed laser deposition(PLD) process on $Al_2$ $O_3$substrate after irradiating the surface of the ZnO sintered pellet by the ArF(193 nm) excimer laser. The epilayers of ZnO were achieved on sapphire(A $l_2$ $O_3$) substrate at a temperature of 400 $^{\circ}C$. The crystalline structure of epilayer was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are 8.27${\times}$$10^{16}$$cm^{-3}$ and 299 $\textrm{cm}^2$/Vㆍs at 293 K, respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}$(T)= 3.3973 eV - (2.69 ${\times}$ 10$_{-4}$ eV/K) $T^2$(T＋463k). After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Zn}$ , $V_{o}$ , Z $n_{int}$, and $O_{int}$ obtained by PL measurements were classified as a donors or accepters type. In addition, we concluded that the heat-treatment in the oxygen atmosphere converted ZnO thin films to an optical p-type. Also, we confirmed that vacuum in ZnO/A $l_2$ $O_3$did not form the native defects because vacuum in ZnO thin films existed in the form of stable bonds.s.s.s.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.41-41
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• 2009

We utilized atomic layer deposition (ALD) for the growth of the ZnO channel layers in the oxide thin-film-transistors (TFTs) with a bottom-gate structure using a $SiO_2/p-Si$ substrate. For fundamental study, the effect of the channel thickness and thermal treatment on the TFT performance was investigated. The growth modes for the ALD grown ZnO layer changed from island growth to layer-by-layer growth at thicknesses of > 7.5 nm with highly resistive properties. A channel thickness of 17 nm resulted in the good TFT behavior with an onloff current ratio of > $10^6$ and a field effect mobility of 2.9 without the need for thermal annealing. However, further increases in the channel thickness resulted in a deterioration of the TFT performance or no saturation. The ALD grown ZnO layers showed reduced electrical resistivity and carrier density after thermal treatment in oxygen.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.262-267
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• 2000

To tap the possibility of exploiting the precipitates as flux-pinning center in the Bi-2223 superconducting system, as-received Bi-2223/Ag tapes with the starting composition of Bi$_{1.8}$Pb$_{0.4}$Sr$_2$Ca$_{2.2}$Cu$_3$O$_8$ were post-annealed at various temperature, oxygen partial pressure, and annealing time. The 2$^{nd}$ phases in the annealed specimen were analysed with XRD, SEM, TEM, and EDS. The size and the distribution of the precipitates such as (Ca,Sr)$_2$(Pb,Bi)O$_4$ and Bi$_{0.5}$Pb$_3$Sr$_2$Ca$_2$CuO$_{12+{\delta}}$ (3221) in the Bi-2223 matrix was controllable by varying heat-treatment condition without breaking the connectivity of the 2223 grains. The nano-size precipitates within the 2223 grains are conjectured as working as flux-pinning sites, resulting in increased J$_c$ value.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.1
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• pp.44-50
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• 1993

In an attempt to improve the electrical characteristics of tantalum pentoxide dielectric film, silicon substrate was reacted with a nitrogen plasma to form a silicon nitride of 50.angs. and then tantalum pentoxide thin films were formed by reactive sputtering in the same chamber. Breakdown field and leakage current density were measured to be 2.9 MV/cm and 9${\times}10^{8}\;A/cm^{2}$ respectively in these films whose thickness was about 180.angs.. With annealing at rectangular waveguides with a slant grid are investigated here. In particular, 900.deg. C in oxygen ambient for 100 minutes, breakdown field and leakage current density were improved to be 4.8 MV/cm and 1.61.6${\times}10^{8}\;A/cm^{2}$ respectively. It turned out that the electrical characteristics could also be improved by oxygen plasma post-treatment and the conduction mechanism at high electric field proved to be Schottky emission in these double-layered films.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2067-2072
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• 2013

Hydrogen ($H_2$) treatment using a two-step $TiO_2$ nanotube (TONT) film was performed under various annealing temperatures from $350^{\circ}C$ to $550^{\circ}C$ and significantly influenced the extent of hydrogen treatment in the film. Compared with pure TONT films, the hydrogen-treated TONT (H:TONT) film showed substantial improvement of material features from structural, optical and electronic aspects. In particular, the extent of enhancement was remarkable with increasing annealing temperature. Light absorption by the H:TONT film extended toward the visible region, which was attributable to the formation of sub-band-gap states between the conduction and valence bands, resulting from oxygen vacancies due to the $H_2$ treatment. This increased donor concentration about 1.5 times higher and improved electrical conductivity of the TONT films. Based on these analyses and results, photoelectrochemical (PEC) performance was evaluated and showed that the H:TONT film prepared at $550^{\circ}C$ exhibited optimal PEC performance. Approximately twice higher photocurrent density of 0.967 $mA/cm^2$ at 0.32 V vs. NHE was achieved for the H:TONT film ($550^{\circ}C$) versus 0.43 $mA/cm^2$ for the pure TONT film. Moreover, the solar-to-hydrogen efficiency (STH, ${\eta}$) of the H:TONT film was 0.95%, whereas a 0.52% STH efficiency was acquired for the TONT film. These results demonstrate that hydrogen treatment of TONT film is a simple and effective tool to enhance PEC performance with modifying the properties of the original material.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.2
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• pp.95-102
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• 2001

Hafnium oxide thin films for gate dielectric were deposited at $300^{\circ}C$ on p-type Si (100) substrates by plasma enhanced chemical vapor deposition (PECVD) and annealed in $O_2$ and $N_2$ ambient at various temperatures. The effect of hydrogen treatment in 4% $H_2$ at $350^{\circ}C$ for 30 min on the electrical properties of $HfO_2$for gate dielectric was investigated. The flat-band voltage shifts of $HfO_2$capacitors annealed in $O_2$ambient are larger than those in $N_2$ambient because samples annealed in high oxygen partial pressure produces the effective negative charges in films. The oxygen loss in $HfO_2$films was expected in forming gas annealed samples and decreased the excessive oxygen contents in films as-deposited and annealed in $O_2$ or $N_2$ambient. The CET of films after hydrogen forming gas anneal almost did not vary compared with that before hydrogen gas anneal. Hysteresis of $HfO_2$films abruptly decreased by hydrogen forming gas anneal because hysteresis in C-V characteristics depends on the bulk effect rather than $HfO_2$/Si interface. The lower trap densities of films annealed in $O_2$ambient than those in $N_2$were due to the composition of interfacial layer becoming closer to $SiO_2$with increasing oxygen partial pressure. Hydrogen forming gas anneal at $350^{\circ}C$ for samples annealed at various temperatures in $O_2$and $N_2$ambient plays critical role in decreasing interface trap densities at the Si/$SiO_2$ interface. However, effect of forming gas anneal was almost disappeared for samples annealed at high temperature (about $800^{\circ}C$) in $O_2$ or $N_2$ambient.