• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.3
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• pp.268-272
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• 2007

A fully integrable InP/InGaAs HPT with an ITO emitter contact was first fabricated by employing a $SiO_2$ passivation layer. The electrical and the optical characteristics of the HPT with a passivation layer were measured and compared with those of the HPT without a passivation layer. The only noticeable difference was the increased emitter series resistance of the HPT with a passivation layer. AES analysis was performed to explain the reason of the increased emitter series resistance. Results show that PECVD $SiO_2$ deposition and annealing processes cause the diffusion of oxygen to the interface and the depletion of tin at the interface, which may be responsible for the increase of the series resistance.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.5
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• pp.380-386
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• 1991

Hydrogen plasma-assisted epitaxial(PAE) growth of GaAs/Si and GaAs/Ge/Si with Ge buffer layer has been investigated. By means of photoluminescence, Nomarski microscopu, and $\alpha$-step, it could be known that GaAs on Si with Ge buffer layer has better crystalline quality than GaAs on Si without Ge buffer layer. The stoichiometry of GaAs layer on Si was confirmed by the depth profile of Auger electron spectroscope (AES). Also the native oxide(SiO$_2$) layer on Si substrate was plama-etched and the removal of the oxide layer was confirmed by AES. Photoluminescence peak wavelength of GaAs/Ge/Si with Ge buffer of 1\ulcorner thickness and GaAs growth rate of 160$\AA$/min was 8700$\AA$and FWHM was 12$\AA$.

• Korean Journal of Materials Research
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• v.2 no.1
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• pp.27-34
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• 1992

Tantalum silicide films are prepared from a composite $TaSi_{28}$ target source and subjected to rapid thermal annealing($500-1100^{\circ}C$, 20sec) in Ar ambient. The formation and the properties of tantalum silicides have been investigated by using 4-point probe, x-ray diffraction, scanning electron microscope(SEM), Auger electron spectroscope(AES), and ${\alpha}$-step. It has been found that the sample annealed above $700^{\circ}C$ forms a polycrystalline $TaSi_2$ phase, and grains grow in granular form regardless of the kind of substrates. The mechanism of the formation of tantalum silicide is the nucleation and growth by Ta-Si short range reaction. The tantalum silicide film has the relatively low resistivity($70-72.5{\mu}{\Omega}-cm$) and smooth surface roughness.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.61-61
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• 2009

This paper has been performed in order to figure out the reason of failure in T23 weldments used for boiler tube at 550 $^{\circ}C$. Defects such as cracks and cavities occurred in CGHAZ (coarse grain heat-affected-zone) and multi pass of weld metal, and these crack propagated along grain boundary. Microstructure evolution such as grain growth and carbide precipitation was investigated by optical microscope (OM), transmission electron microscope(TEM). Moreover, Auger electron spectroscope (AES) was employed in order to examine segregation along the grain boundaries. There is significant difference in grain size and precipitation distribution in the region where cracking took place. In addition, sulfur segregation was observed. Based on the results of this investigation, it has been possible to establish that this type of cracks were consistent with reheat cracking and creep damage. Selection of optimal filler metal, heat input, and PWHT temperature is required for prevention in order to avoid this type of cracking.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.130-132
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• 2003

ALD(Atomic Layer Deposition) 법으로 박막 알루미나를 형성한 후 웨이퍼 접합과 박막화 공정으로 알루미나를 매몰절연막으로 하는 SOI 구조를 제조하고 그 특성을 조사하였다. 알루미나 박막의 유전 특성과 실리콘과의 계면 특성은 C-V 측정으로, 단면 분석은 SEM(Scanning Electron Microscope) 촬영으로 조사하였다. 알루미나와 실리콘을 접합하기 위하여 1100C에서 열처리를 행한 후 알루미나와 실리콘의 계면 상태 밀도는 $2.5{\times}10^{11}/cm^2-eV$였다. 그리고 SEM의 단연 분석과 AES(Auger Electron Spectroscope)의 깊이 방향 분석을 통해서 매몰 알루미나층의 존재를 확인하였다. 알루미나는 실리콘 산화막보다 높은 열전도성을 가지므로 이를 매몰절연막으로 하여 SOI 구조를 제조하면 기존의 실리콘산화막을 매몰절연막으로 하는 SOI를 기판으로 하여 제조되는 소자보다 selg heating 효과가 감소된 우수한 특성의 소자를 제조할 수 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.444-445
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• 2007

IZO/Al multilayer anode films for flexible top emitting organic light emitting diodes (TOLEDs) were grown on PEN (polyethylen-enaphthelate) substrate using twin target sputter (TTS) system. To investigate electrical and optical properties of IZO/Al multilayer films, 4-point probe method and UV/Vis spectrometer were used, respectively. From a IZO/Al multilayer films with 100nm-thick Al, sheet resistance of $1.4{\Omega}/{\square}$ and reflectance of above 62% at a range of 500~550nm wavelength could be obtained, In addition, structural and surface properties of IZO/Al multilayer films were analyzed by XRD (X-ray diffraction) and FESEM (field emission scanning electron microscopy) and AES (auger electron spectroscope), respectively. Moreover, flexibility of IZO/Al multilayer anode films were examined by bending test method.

• Korean Journal of Materials Research
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• v.5 no.3
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• pp.357-363
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• 1995

PECVD(Plasma-enhanced Chemical Vapor Deposition)법을 이용하여 증착한 $Ta_{2}$O_{5}$ 박막의 전기적 특성과 미세구조에 미치는 RTA(Rapid Thermal annealing) 후속 고온 열처리의 영향을 조사하였다. $Ta_{2}$O_{5}$ 박막의 미세구조와 interface 거동을 관찰하기 위하여XRD(X-ray Diffractometer), TEM(Transmission Electron Microscope), AES(Auger Electron Spectroscope) 분석을 실시하였으며, 전기적 특성을 관찰하기 위하여 I-V, C-V 측정을 하였다. $600^{\circ}C$에서 60초간 열처리를 실시하였을 경우 가장 우수한 유전 특성 및 누설 전류 특성을 보였으며, 유전 상수는 26이었고 누설 전류는 5 $\times$ $10^{-11}$A/$cm^{2}$이었다. $600^{\circ}C$ 이상의 온도에서 행한 열처리에 의하여 박막의 누설 전류와 유전 특성은 복합적으로 영향을 받았음을 알 수 있었다. 이는 $600^{\circ}C$의 열처리에서 이루어지고있는 박막의 결함감소와 고밀화 현상과 함께 80$0^{\circ}C$ 이상의 열처리에서 발생하는 조밀육방정 결정 구조를 가지는 $\delta$-$Ta_{2}$O_{5}$의 결정화에 기인함을 알 수 있었다. 또한 TEM과 AES분석 결과로부터 이들 박막의 누설 전류와 유전상수의 변화는 열처리에 의하여 일어나는 Ta-O-Si transition층의 생성과 성장에 기인함을 알 수 있었다. 따라서 $Ta_{2}$O_{5}$ 박막의 전기적 특성의 변화는 RTA 후속 열처리에 따른 계면 반응과 결정화 그리고 박막의 조밀화에 그 영향이 있음을 알 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.25-32
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• 2007

We investigated the silicide reaction stability between 10 nm-Col-xNix alloy films and silicon substrates with the existence of 4 nm-thick natural oxide layers. We thermally evaporated 10 nm-Col-xNix alloy films by varying $x=0.1{\sim}0.9$ on naturally oxidized single crystal and 70 nm-thick polycrystalline silicon substrates. The films structures were annealed by rapid thermal annealing (RTA) from $600^{\circ}C$ to $1100^{\circ}C$ for 40 seconds with the purpose of silicidation. After the removal of residual metallic residue with sulfuric acid, the sheet resistance, microstructure, composition, and surface roughness were investigated using a four-point probe, a field emission scanning electron microscope, a field ion bean4 an X-ray diffractometer, and an Auger electron depth profiling spectroscope, respectively, to confirm the silicide reaction. The residual stress of silicon substrate was also analyzed using a micro-Raman spectrometer We report that the silicide reaction does not occur if natural oxides are present. Metallic oxide residues may be present on a polysilicon substrate at high silicidation temperatures. Huge residual stress is possible on a single crystal silicon substrate at high temperature, and these may result in micro-pinholes. Our results imply that the natural oxide layer removal process is of importance to ensure the successful completion of the silicide process with CoNi alloy films.