• 한국진공학회지
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• 제2권1호
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• pp.28-33
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• 1993

산화분위기에서의 Ti/SiO2 박막의 산화거동 및 계면반응을 조사했다. SiO2막위에 100nm의 티타니움을 스퍼터법으로 형성하여 급속가열로(Rapid Thermal Processor)에서 온도를 달리하여 산화시켰다. 산화거동은 박막의 면저항의 측정, 산화막 두께측정, XPS(X-ray Photoelectron Spectroscopy)에 의한 조성분석으로 평가했다. 산화시 티타니움 면저항은 표면에서 산화로 인해 약 $500^{\circ}C$ 이상에서 증가하기 시작해서 $800^{\circ}C$에서 포화되었다. 이 때 막두께는 약 $700^{\circ}C$ 이상에서 약 2배로 증가한 후 일정한 두께를 나타내었다. 이 결과로부터 산화부산물에 도전성물질이 존재하는 것을 알 수 있었다. TEM과 XPS분석결과 40$0^{\circ}C$ 이상에서 산화시 Ti 표면에서부터 TiO2가 형성되고 $600^{\circ}C$ 이상에서는 TiO2의 형성과 Si의 석출이 확인되었다. 석출되는 Si의 양은 온도에 따라 증가했다.

• 전자공학회논문지A
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• 제30A권11호
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• pp.105-112
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• 1993

Oxide and reoxidized-nitrided-oxide were formed by furnace oxidation and rapid thermal processing (RTP). MOS capacitor and n-MOSFET's with those films as gate insulators were fabricated. The electrical characteristics of insulators were evaluated by current-voltage, high-frequency capacitance-voltage (C-V), and time-dependent dielectrical breakdown (TDDB) measurements. The hot carrier effects of MOSFET's were also investigated. Time-dependent dielectrical breakdown (TDDB) characteristics show that the life time of reoxidized-nitrided-oxide films is about 3 times longer than that of oxides. Hot carrier effects reveal that the life time of MOSFET's with reoxidized-nitrided-oxides is about 3 times longer than that of MOSFET's with oxides. Therefore, it is found that the reliability of dielectric films estimated by the hot carrier effects of MOSFET's is consistent with that of dielectric films from TDDB method.

• 한국재료학회지
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• 제22권4호
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• pp.202-206
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• 2012

$CoSi_2$ was formed through annealing of atomic layer deposition Co thin films. Co ALD was carried out using bis(N,N'-diisopropylacetamidinato) cobalt ($Co(iPr-AMD)_2$) as a precursor and $NH_3$ as a reactant; this reaction produced a highly conformal Co film with low resistivity ($50\;{\mu}{\Omega}cm$). To prevent oxygen contamination, $ex-situ$ sputtered Ti and $in-situ$ ALD Ru were used as capping layers, and the silicide formation prepared by rapid thermal annealing (RTA) was used for comparison. Ru ALD was carried out with (Dimethylcyclopendienyl)(Ethylcyclopentadienyl) Ruthenium ((DMPD)(EtCp)Ru) and $O_2$ as a precursor and reactant, respectively; the resulting material has good conformality of as much as 90% in structure of high aspect ratio. X-ray diffraction showed that $CoSi_2$ was in a poly-crystalline state and formed at over $800^{\circ}C$ of annealing temperature for both cases. To investigate the as-deposited and annealed sample with each capping layer, high resolution scanning transmission electron microscopy (STEM) was employed with electron energy loss spectroscopy (EELS). After annealing, in the case of the Ti capping layer, $CoSi_2$ about 40 nm thick was formed while the $SiO_x$ interlayer, which is the native oxide, became thinner due to oxygen scavenging property of Ti. Although Si diffusion toward the outside occurred in the Ru capping layer case, and the Ru layer was not as good as the sputtered Ti layer, in terms of the lack of scavenging oxygen, the Ru layer prepared by the ALD process, with high conformality, acted as a capping layer, resulting in the prevention of oxidation and the formation of $CoSi_2$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.142-145
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• 2004

In this work, we have investigated the application of rapid thermal processing (RTP) and plasma enhanced chemical vapour deposition (PECVD) for surface passivation. Rapid thermal oxidation (RTO) has sufficiently low surface recombination velocities (SRV) $S_{eff}$ in spite of a thin oxides and short process time. The effective lifetime is increasing with an increase of the oxide thickness. In the same oxide thickness, The effective lifetime is independent on the process temperature and time. $S_{eff,max}$ is exponentially decreased with increasing oxide thickness. $S_{eff,max}$ can be reduced to 200 cm/s with only 10 nm oxide thickness. On the other hand, three different types of SiN are reviewed. SiN1 layer has a thickness of about 72 nm and a refractive index of 2.8. Also, The SiN1 has a high passivation quality. The effective lifetime and SRV of 1 $\Omega$ cm Float zone (FZ) silicon deposited with SiN1 is about 800 s and under 10 cm/s, respectively. The SiN2 is optimized for the use as an antireflection layer since a refractive index of 2.3. The SiN3 is almost amorphous silicon caused by less contents of N2 from total process. The effective lifetime on the FZ 1 ${\Omega}cm$ is over 1000 ${\mu}s$.

• 한국진공학회지
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• 제6권1호
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• pp.28-35
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• 1997

급속열처리에 따른 (hfac)Cu(VTMS)구리원으로 증착한 구리 박막의 특성개선 효과 와 TiN층의 확산방지 특성의 변화를 고찰하였다. 구리 박막의 특성 변화는 열처리 시간보 다 열처리 온도의 변화에 더 민감하며, 후열처리에 의해 Cu/TiN구조의 전기적 특성과 더불 어 미세구조 변화가 뚜렷하게 나타났다. $400^{\circ}C$이상에서 면저항의 증가가 시작되어 $600^{\circ}C$이 상에서 구리와 TiN의 상호 반응과 구리박막 표면에서의 산화물 형성이 관찰되었다. 후열처 리에 의한 결정립 성장은 (111)배향을 나타내었고, $500^{\circ}C$에서 결정립의 성장이 가장 활발하 게 나타났다. MOCVD-Cu/PVD-TiN구조에서 TiN층의 확산방지 특성을 충분히 유지시키면 서 구리 박막의 전기적 특성을 개선시킬 수 있는 열처리 공정 온도는 $400^{\circ}C$정도가 적정한 것으로 판단되었다.

• Advances in aircraft and spacecraft science
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• 제4권1호
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• pp.37-52
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• 2017

Gas turbines operating in dusty or sandy environment polluted with micron-sized solid particles are highly prone to blade surface erosion damage in compressor stages and molten sand attack in the hot-sections of turbine stages. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains in the middle eastern countries or in volcanic zones; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on the durability of these engines as well as performance. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The focus of this research work is to simulate particle-surface kinetic interaction on typical turbomachinery material targets using non-linear dynamic impact analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and to develop sand-phobic thermal barrier coatings for turbine blades. This paper outlines the research efforts at the U.S Army Research Laboratory to come up with novel turbine blade multifunctional protective coatings that are sand-phobic, sand impact wear resistant, as well as have very low thermal conductivity for improved performance of future gas turbine engines. The research scope includes development of protective coatings for both nickel-based super alloys and ceramic matrix composites.

• JSTS:Journal of Semiconductor Technology and Science
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• 제1권4호
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• pp.202-208
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• 2001

In Recent results suggested that doping $Ta_2O_5$ with a small amount of $TiO_2$ using standard ceramic processing techniques can increase the dielectric constant of $Ta_2O_5$ significantly. In this paper, this concept is studied using RTCVD (Rapid Thermal Chemical Vapor Deposition). Ti-doped $Ta_2O_5$ films are deposited using $TaC_{12}H_{30}O_5N$, $C_8H_{24}N_4Ti$, and $O_2$ on both Si and $NH_3$-nitrided Si substrates. An $NH_3$-based interface layer at the Si surface is used to prevent interfacial oxidation during the CVD process and post deposition annealing is performed in $H_2/O_2$ ambient to improve film quality and reduce leakage current. A sputtered TiN layer is used as a diffusion barrier between the Al gate electrode and the $TaTi_xO_y$ dielectric. XPS analyses confirm the formation of a ($Ta_2O_5)_{1-x}(TiO_2)_x$ composite oxide. A high quality $TaTi_xO_y$ gate stack with EOT (Equivalent Oxide Thickness) of $7{\AA}$ and leakage current $Jg=O.5A/textrm{cm}^2$ @ Vg=-1.0V has been achieved. We have also succeeded in forming a $TaTi_x/O_y$ composite oxide by rapid thermal oxidation of the as-deposited CVD TaTi films. The electrical properties and Jg-EOT characteristics of these composite oxides are remarkably similar to that of RTCVD $Ta_2O_5, suggesting that the dielectric constant of $Ta_2O_5$ is not affected by the addition of $TiO_2$.

• 한국산학기술학회논문지
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• 제7권5호
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• pp.811-816
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• 2006

이방성 자기저항효과(anisotropic magnetoresistance : AMR)는 단층 자성박막으로 구성되므로 경제성 있게 박막화 시켜서 소형화가 가능하다. 기존의 급속응고법으로 생산된 리본형 MCo(M=Cu, Ag) 소자가 경제적으로 공업적 목적을 달성하였으나, 리본형 특유의 두께와 가공성이 부족하여 소형 소자에 함께 집적하기 곤란한 단점이 있었다. 새로운 박막형을 쓰면 추가 열처리 없이 기존의 리본형 소자와 비교하여 박막상태로 적절한 AMR 특성이 나오는지와 최적 AMR을 얻기 위한 Co의 조성을 아는 것이 중요하다. 열증착기를 써서 100nm의 $Cu_{1-x}Co_x$와 $Ag_{1-x}$ 박막을 Co의 조성을 $10{\sim}70wt%$로 달리하며 제작하여 이때의 자기적 특성을 확인하였다. CuCo는 40% Co에 0.5T에서 1.4%, AgCo는 30% Co에 2.6%의 MR비를 얻었고 이는 리본형 소자보다는 표면 산란 효과에 의해 MR비는 작지만 표면산화막 없이 직접 다른 소자공정과 함께 진행할 수 있는 장점이 있음을 확인하였다.

• 한국수소및신에너지학회논문집
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• 제24권1호
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• pp.29-35
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• 2013

A dense mixed ionic and electronic conducting ceramic membrane is one of the most promising materials because it can be used for separation of oxygen from the mixture gas. The $ABO_3$ perovskite structure shows high chemical stability at high temperatures under reduction and oxidation atmospheres. $BaCo_{1-x-y}Fe_xZr_yO_{3-{\delta}}$ (BCFZ) was well-known material as high mechanical strength, low thermal conductivity and stability in the high valence state. Glycine Nitrate Process (GNP) is rapid and effective method for powder synthesis using glycine as a fuel and show higher product crystallinity compared to solid state reaction and citrate-EDTA method. BCFZ was fabricated by modified glycine nitrate process. In order to control the burn-up reaction, $NH_4NO_3$ was used as extra nitrate. According to X-Ray Diffraction (XRD) results, BCFZ was single phase regardless of Zr dopants from y=0.1 to 0.3 on B sites. The green compacts were sintered at $1200^{\circ}C$ for 2 hours. Oxygen permeability, methane partial oxidation rate and hydrogen production ability of the membranes were characterized by using Micro Gas Chromatography (Micro GC) under various condition. The high oxygen permeation flux of BCFZ 1-451 was about $1ml{\cdot}cm^{-2}s^{-1}$. Using the humidified Argon gas, BCFZ 1-433 produced hydrogen about $1ml{\cdot}cm^{-2}s^{-1}$.

• 한국재료학회지
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• 제6권5호
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• pp.489-493
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• 1996

다공질 실리콘층(Porous Silicon LayerLPSL)을 사용하여 저온 열산화 (50$0^{\circ}C$, 1시간)와 급속 열산화공정(rapid thermal oxidationLRTO)(115$0^{\circ}C$, 1분)을 통하여 저온 산화막을 제조하였다. 제조된 산화막의 특성을 IR흡수 스펙트럼, C-V 곡선, 절연파괴전압, 누설전류, 그리고 굴절률을 조사함으로써 알아보았다. 절연파괴전압은 2.7MV/cm, 누설전류는 0-50V 범위에서 100-500pA의 값을 보였다. 산화막의 굴절률은 1.49의 값으로서 열산화막의 굴절률에 근접한 값을 나타냈다. 이 결과로부터 다공질 실리콘층을 저온산화막으로 제조할 때, RTO공정이 산화막의 치밀화(densification)에 크게 기여함을 알 수 있었다.