• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.78-84
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• 2003

Boron carbide thin coatings were deposited on silicon wafers by DC magnetron sputtering using a $B_4C$ target with As as processing gas. Various amounts of methane gas $(CH_4)$ were added in the deposition process to better understand their influence on tribological properties of the coatings. Reciprocating wear tests employing an oscillating friction wear tester were performed to investigate the tribological behaviors of the coatings in ambient environment. The chemical characteristics of the coatings and worn surfaces were studied using X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). It revealed that $CH_4$ addition to As processing gas strongly affected the tribologcal properties of sputtered boron carbide coating. The coefficient of friction was reduced approximately from 0.4 to 0.1, and wear resistance was improved considerably by increasing the ratio of $CH_4$, gas component from 0 to $1.2\;vol\;\%$. By adding a sufficient amount of $CH_4\;(1.2\%)$ in the deposition process, the boron carbide coating exhibited lowest friction and highest wear resistance.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.309-309
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• 2011

There have been large research activities on the high quality oxide films for the realization oxide based electronics. However, the interface interdiffusion prohibits achieving high quality oxide films, when the oxide films are grown on non-oxide substrates. In the case of Si substrates, there exist lattice mismatch and interface interdiffusion when oxide films deposited on direct Si surface. In this presentation, we report the interface characteristics of yttria-stabilized zirconia films grown on silicon substrates. From x-ray reflectivity analysis we found that the film thickness and interface roughness decreased as the growth temperature increased, indicating that the growth mechanism varies and the chemical reaction is limited to the interface as the growth condition varies. Furthermore, the packing density of the film increased as the growth temperature increased and the film thickness decreased. X-ray photoelectron spectroscopy analysis of very thin films revealed that the amount of chemical shift increased as the growth temperature increased. Intriguingly, the direction of the chemical shift of Zr was opposite to that of Si due to the second nearest neighbor interaction.

• 폴리머
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• 제33권3호
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• pp.263-267
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• 2009

d-PMMA(deuterated poly(methyl methacrylate)) 박막 표면의 친수성을 향상시키기 위해 산소 플라즈마에 노출시켰다. 이 때 모든 조건은 동일하며, 플라즈마에 대한 노출 시간만을 0초에서 180초까지 변화를 주어 노출 시간에 대한 영향을 접촉각과 X-ray 반사율 장치, 중성자 반사율 장치, XPS(X-ray photoelectron spectroscopy)를 이용해 조사하였다. 노출 시간이 증가할수록 물 접촉각은 작아지며, 산소의 조성은 커짐을 확인함으로써 산소의 조성이 친수성 향상에 큰 영향을 미치는 것을 확인할 수 있었다. 또한, X-ray 반사율 장치를 이용해 얻은 에칭률을 통해서 d-PMMA 박막에 대한 산소 플라즈마의 노출 시간에 따른 물리적 특성을 연구하였으며, X-ray 반사율과 중성자 반사율, 그리고 XPS 측정 결과로부터 산소와 탄소의 조성뿐만 아니라 수소의 조성까지도 얻음으로써 플라즈마 처리된 박막의 화학적 성질을 보다 자세히 연구할 수 있었다.

• 한국진공학회지
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• 제2권2호
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• pp.171-180
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• 1993

X-선 광전자 분광법(XPD)을 이용하여 GaAs(110) 절개면의 결정구조를 이해하였다. 각분해 X-선 분광법으로 GaAs(110) 면의 내각준위 Ga 및 As 3d의 스펙트럼을 얻어, 이 내각 준위의 세기 비율(intensity ratio)의 방위각과 편각에 따른 변화를 SSC(Single Scattering Cluster) 모델에서 얻은 회절패턴으로 곡선분석(fitting)하여 절개면의 재구성 구조(reconstruction geometry)를 얻었다. 이 절개면의 재구성된 값은 다른 실험의 결과와 비슷하였다.

• 한국진공학회지
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• 제18권4호
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• pp.281-287
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• 2009

본 연구에서는 고진공 조건에서 열기화 증착 방법으로 산화막으로 덮인 Mg 리본(MgO/Mg) 위에 Pd을 증착하였다. 고진공 속에서 만든 시료의 전자구조를 in-situ X-선 광전자 분광법 (XPS)을 통하여 분석하였고, 분석 후, FE-SEM을 통해 증착량의 증가에 따른 표면구조의 변화를 확인하였다. Pd 증착량이 1 나노미터 (nm) 이하인 경우에는 증착량 증가에 따른 Pd 나노입자 크기의 증가를 확인하였으며, Pd을 1 nm 이상의 두께로 증착시킨 경우에는 Pd 입자들의 뭉침에 의해 얇은 필름이 형성됨을 관찰하였다. Pd과 기판사이의 전하이동에 의하여 산화물/금속 계면의 Pd 원자들은 부분적으로 양전하를 띔을 확인하였다.

• Transactions on Electrical and Electronic Materials
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• 제15권4호
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• pp.221-225
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• 2014

Although gold wire bonding techniques have already matured in semiconductor manufacturing, weakly bonded wires in semiconductor chip assembly can jeopardize the reliability of the final product. In this paper, weakly bonded or failed aluminum bonding pads are analyzed using X-ray photoelectron spectroscopy (XPS), Auger electron Spectroscopy (AES), and energy dispersive X-ray analysis (EDX) to investigate potential contaminants on the bond pad. We found the source of contaminants is related to the dry etching process in the previous manufacturing step, and fluorocarbon plasma etching of a passivation layer showed meaningful evidence of the formation of fluorinated by-products of $AlF_x$ on the bond pads. Surface analysis of the contaminated aluminum layer revealed the presence of fluorinated compounds $AlOF_x$, $Al(OF)_x$, $Al(OH)_x$, and $CF_x$.

• 대한화학회지
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• 제55권5호
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• pp.812-818
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• 2011

[ $V_{0.9}Sb_{0.1}O_x$ ]systems, bulk and deposited on different supports (five types of ${\gamma}$-aluminas, ${\alpha}$-alumina, silica-alumina, silica gel, magnesium oxide), have been tested in the oxidative dehydrogenation (ODH) of iso-butane. This statement is derived from the data obtained by a set of characterisation techniques(specific surface area measurements, X-ray diffraction, X-ray photoelectron spectroscopy, laser Raman spectroscopy, in situ differential scanning calorimetry and in situ diffuse reflectance-absorption infrared Fourier transform spectroscopy).

• 한국자기학회지
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• 제16권1호
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• pp.18-22
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• 2006

바나듐(V)도핑이 $Fe_3O_4$의 자기적 성질에 미치는 영향을 조사하기 위하여 졸-겔 방법을 이용하여 $V_xFe_{3-x}O_4$ 박막들을 제작하고, x-ray diffraction(XRD), x-ray photoelectron spectroscopy(XPS), conversion electron Mossbauer spectroscopy(CEMS), vibrating sample magnetometry(VSM) 등을 이용하여 그 구조적, 자기적 특성들을 측정 및 분석하였다. XRD 측정 결과에 따르면 $V_xFe_{3-x}O_4$ x=1.0까지 입방(cubic)구조를 유지하며, 그 격자 상수는 거의 변화하지 않았다. 바나듐의 2p 및 철의 2p 준위들에 대한 XPS 측정 및 분석 결과, 바나듐은 화합물 내에서 주로 +3가의 상태로 존재하며, 성분비 x가 증가함에 따라 +2가 이온의 농도가 증가함이 나타났다. CEMS측정 결과 $V^{3+}$이온들은 사면체 $Fe^{3+}$자리를 주로 치환하며, $Fe^{2+}$이온들은 팔면체 $Fe^{2+}$자리를 치환하는 것으로 나타났다. 박막들에 대한 상온에서의 VSM측정 결과, 바나듐을 작은 양 도핑 할 경우(x=0.14) $V_xFe_{3-x}O_4$의 포화자화량(saturation magnetization)은 $Fe_3O_4$ 비하여 증가함이 나타났으며, 다량 도핑 할 경우$(x\geq0.5) Fe_3O_4$에 비하여 점차적으로 감소함이 나타났다. $V_xFe_{3-x}O_4$의 보자력(coercivity)은 x의 증가에 따라 증가함이 나타났는데, $V^{2+}(d^3)$ 이온의 팔면체 자리 치환에 의한 비등방성의 증가에 기인하는 것으로 해석된다.

• Carbon letters
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• 제13권1호
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• pp.44-47
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• 2012

We analyzed the effect of etchants for metal catalysts in terms of the characteristics of resulting graphene films, such as sheet resistance, hall mobility, transmittance, and carrier concentration. We found the residue of $FeCl_3$ etchant degraded the sheet resistance and mobility of graphene films. The residue was identified as an iron oxide containing a small amount of Cl through elemental analysis using X-ray photoelectron spectroscopy. To remove this residue, we provide an alternative etching solution by introducing acidic etching solutions and their combinations ($HNO_3$, HCl, $FeCl_3$ + HCl, and $FeCl_3+HNO_3$). The combination of $FeCl_3$ and acidic solutions (HCl and $HNO_3$) resulted in more enhanced electrical properties than pure etchants, which is attributed to the elimination of left over etching residue, and a small amount of amorphous carbon debris after the etching process.

• 대한금속재료학회지
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• 제50권8호
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• pp.549-556
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• 2012

The tribological behavior of CrMoN films with respect to surface chemistry was investigated by using X-ray photoelectron spectroscopy (XPS). All of the films were prepared from a hybrid PVD system consisting of DC unbalanced magnetron (UBM) sputtering and arc ion plating (AIP) sources. The tribological property of the films was evaluated by a friction coefficient using a Ball-on-disk type tribometer. The chemistry of wear track was analyzed by energy dispersive spectroscopy (EDS) and XPS. The friction coefficient was measured to be 0.4 for the CrMoN film, which is lower than that of a monolithic CrN film. EDS and XPS results imply the formation of an oxide layer on the coating surface, which was identified as molybdenum oxide phases, known to be a solid lubricant during the wear test.