• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.12
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• pp.1091-1098
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• 1998

Thermal stability of the electroless deposited Cu thin film was investigated. Cu/TaN/Si multilayer was fabricated by electroless-depositing Cu thin layer on TaN diffusion barrier layer which was deposited by MOCVD on the Si substrate, and was annealed in $H_2$ ambient to investigate the microstructure of Cu film with a post heat-treatment. Cu thin film with good adhesion was successfully deposited on the surface of the TaN film by electroless deposition with a proper activation treatment and solution control. Microstructural property of the electroless-deposited Cu layer was improved by a post-annealing in the reduced atmosphere of $H_2$ gas up to $600^{\circ}C$. Thermal stability of Cu/TaN/Si system was maintained up to $600^{\circ}C$ annealing temperature, but the intermediate compounds of Cu-Si were formed above $650^{\circ}C$ because Cu element passed through the TaN layer. On the other hand, thermal stability of the Cu/TaN/Si system in Ar ambient was maintained below $550^{\circ}C$ annealing temperature due to the minimal impurity of $O_2$ in Ar gas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.6
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• pp.580-585
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• 2004

Silicon dioxide (SiO$_2$) is widely used as a gate dielectric material for thin film transistors (TFT) and semiconductor devices. In this paper, SiO$_2$ films were grown by APCVD(Atmospheric Pressure chemical vapor deposition) at the high temperature. Experimental investigations were carried out as a function of $O_2$ gas flow ratios from 0 to 200 1pm. This article presents the SiO$_2$ gate dielectric studies in terms of deposition rate, refrative index, FT-IR, C-V for the gate dielectric layer of thin film transistor applications. We also study defect passivation technique for improvement interface or surface properties in thin films. Our passivation technique is Forming Gas Annealing treatment. FGA acts passivation of interface and surface impurity or defects in SiO$_2$ film. We used RTP system for FGA and gained results that reduced surface fixed charge and trap density of midgap value.

• Journal of Korean Port Research
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• v.14 no.4
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• pp.451-461
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• 2000

The design and maintenance of navigation channel and water facilities of an harbor which is located at the mouth of river or at the estuary area are difficult due to the complexity of estuarial water and sediment circulation. Effects of deepening navigable waterways, of changing coastline configurations, or of discharging dredged material to the open sea are necessary to be investigated and predicted in terms of water quality and possible physical changes to the coastal environment. A borad analysis of the transport mechanism in the estuary area was made in terms of sediment property, falling velocity, concentration and flow characteristics. In order to simulate the transport processes, a two-dimensional finite element model is developed, which includes erosion, transport and deposition mechanism of suspended sediments. Galerkin’s weighted residual method is used to solve the transient convection-diffusion equation. The fluid domain is subdivided into a series of triangular elements in which a quadratic approximation is made for suspended sediment concentration. Model could deal with a continuous aggregation by stipulating the settling velocity of the flocs in each element. The model provides suspended sediment concentration, bed shear stress, erosion versus deposition rate and bed profile at the given time step.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.110-111
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• 2007

In order to form a p-type ZnO thin film, ZnO thin film is deposited by pulsed laser deposition(PLD) on GaAs substrate followed by nermal treatment that ensures the diffusion of As atoms from the GaAs substrate to the ZnO thin films. Photoluminescence (PL) measurement reveals that the improved qualify of ZnO thin films is acquired at the growth temperature of $400^{\circ}C$. It is ZnO film grown at $100^{\circ}C$ that shows the change from n-type to p-type by the thermal treatment. Measured carrier concentration in the film is changed from $-5.70{\times}10^{13}\;to\;9.09{\times}10^{18}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.9-10
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• 2007

In this paper, Thin films of $HfO_2$/Hf were deposited on p-type wafer by Atomic Layer Deposition(ALD). And we studied the electrical characterization of $HfO_2$/Hf/Si MOS capacitor depending on thickness of Hf metal layer. $HfO_2$ films were deposited using TEMAH and $O_3\;at\;350^{\circ}C$. Samples were then annealed using furnace heating to $500^{\circ}C$. The MOS capacitor of round-type was fabricated on Si substrates. Through TEM(Transmission Electron Microscope), XRD(X-ray Diffraction), capacitance-voltage(C-V) and current-voltage(I-V) analysis, the role of thin Hf metal layer for the better $HfO_2$/Si interface property was investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.212-213
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• 2007

$TiO_2$ 박막은 좋은 내구성 전기적 특성과 함께 가시광선 영역에서의 높은 투과율, 높은 굴절률을 나타내어 태양전지의 반사 방지막, TFT 절연막, 광학적 필터에 쓰이는 다층 광학적 코팅 재료 등에 쓰이며 높은 이용가치로 인해 이에 대한 많은 연구가 이루어지고 있다. 본 논문에서는 APCVD(Atmospheric Pressure Chemical Vapor Deposition)법을 이용하여 $200^{\circ}C$에서 $350^{\circ}C$까지 증착 온도를 변화시키며 $TiO_2$ 박막을 제조할 때 나타나는 광학적 특징 변화에 대한 연구를 수행하였다. 온도가 증가할수록 굴절률은 커지고 $TiO_2$, 박막안의 기공과 결함의 비율은 감소하였다. 광투과율은 UV범위 이후에서 급격한 증가를 보였으며 온도가 증가함에 따라 흡수단이 긴 파장쪽으로 이동하였다. 흡수단의 증가는 광학적 밴드갭과 연관되며 온도가 증가할수록 광학적 밴드갭은 낮아지는 것을 확인할 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.368-368
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• 2007

Zinc oxide (ZnO) has drawn much interest as a potential transparent conducting oxide (TCO) for applying to solar cell and front electrode of electro-luminescent devices. For the enhancement of electrical property of TCOs, dopant introduction and hybridization with conductive nanoparticles have been investigated. In this work, ZnO films were formed on glass substrate by using photochemical solution deposition of Ag nanoparticles dispersed or various metal (Ag, Cd, In, or Sn) contained photosensitive ZnO solutions. The usage of photosensitive solution permits us to obtain a micron-sized direct patterning of ZnO film without using conventional dry etching procedure. The structural, optical, and electrical characteristics of ZnO films with the introduction of metal dopants with/without Ag nanoparticles have been investigated to check whether there is a combined effect between metal dopants and Ag nanoparticles on the characteristics of ZnO film. The phase formation and crystallinity of ZnO film were monitored with X-ray diffractometer. The optical transmittance measurement was carried out using UV-VIS-NIR spectrometer and the electrical properties such as sheet resistance and conductivity were observed by using four-point probe.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.177-182
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• 2013

Transparent thin film transistors (TTFT) were fabricated on $N^+$ Si wafers. $SiO_2$, $Si_3N_4/SiO_2$ and $Al_2O_3/SiO_2$ grown on the wafers were used as gate insulators. The rf magnetron sputtered zinc tin oxide (ZTO) films were adopted as active layers. $N^+$ Si wafers were wet-oxidized to grow $SiO_2$. $Si_3N_4$ and $Al_2O_3$ films were deposited on the $SiO_2$ by plasma enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD), respectively. The mobility, $I_{on}/I_{off}$ and subthreshold swing (SS) were obtained from the transfer characteristics of TTFTs. The properties of gate insulators were analyzed by comparing the characteristics of TTFTs. The property variation of the ZTO TTFTs with time were observed.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.322-325
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• 2008

3,3-Dimethyl-1-butene ($C_6H_{12}$) monomer was deposited using a plasma-enhanced chemical vapor deposition (PECVD) instrument. The more the R.F. power/pressure ratio in FT-IR spectrum, the less the hydrogen quantity and the dangling bond in amorphous carbon films observed so that the mechanical property of the films are improved related to the density. Also, with the increase D peak in Raman spectrum is increased and the ring structure's films are produced. According to these results, hardness and modulus are 12 GPa and 85 GPa, respectively. The refractive index (n) and extinction coefficients (k) of the deposited films are increased with the increase in a power/pressure ratio.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.447-451
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• 1999

Silver has the highest electrical conductivity of all metals and consequently this property is an attractive feature which makes it a leading candidate for use in electronic devices. The research conducted was focused primarily on the development of a process for obtaining a deposited silver-coating onto alumina, for applications related to electrical-conducting devices and, ancillarily, catalysts. Alumina balls and plane substrates were utilized for the investigation. The coating process employed an aqueous ammoniacal silver-nitrate electrolytes with a formaldehyde solution as the reductant. Modifying additives-an activator which would be expected to promote good deposition-characteristics onto the (dielectric) substrate and an inhibitor which would obviate homogeneous reduction (precipitation) of silver was observed when the activator-containing silver-electrolyte reductant constituents were combined. However, the silver-electrolyte/reductant system with inhibitor could be employed (at 8$0^{\circ}C$) to achieve a viable (subject to future research optimization) coating on alumina. The influence of the processing temperature on the deposition process was delineated during the course of the research. The morphology of the deposited-silver on the alumina balls was assessed by SEM imaging. A tape-peel test was employed, with the plane substrates, to semi-quantitatively characterize the adhesion to the alumina.