• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.82-85
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• 2003

The sapphire wafers for blue light emitting devices were manufactured by the implementation of the surface machining technology based on micro-tribology. This process has been performed by Micro-lapping process. The sapphire crystalline wafers were characterized by DCXD(Double Crystal X-ray Diffraction). The sample quality of crystalline sapphire wafer at surface has a FWHM(Full Width at Half Maximum) of 250 arcsec. This value at the sapphire wafer surfaces indicated 0.12${\mu}{\textrm}{m}$ sizes. Surfaces of sapphire wafers were mechanically affected by residual stress and surface default. Also Surfaces roughness of sapphire wafers were measured 2.1 by AFM(Atom Force Microscope).

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.61-62
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• 2002

In order to clarify the contact mechanism between specimen surface and probe tip in the surface observation by the AFM (atomic force microscope) or the FFM (friction force microscope), several molecular dynamics simulations have been performed. In the simulation, a 3-dimensional simulation model is proposed where the specimen and the probe are assumed to consist of mono-crystal line copper and a carbon atom respectively and the effect of cantilever stiffness is also taken into considered. The surface observation process on a well-defined Cu{100} is simulated. The influences of cantilever stiffness on the reactive force images and the behavior of probe tip were evaluated. As a resuIt, several phenomena similar to those observed by the actual surface observation experiment, such as double-slip behavior and dispersion in the stick-slip wave period were observed.

• 한국정밀공학회지
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• 제21권2호
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• pp.218-223
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• 2004

The sapphire wafers for blue light emitting devices were manufactured by the implementation of the surface machining technology based on micro-tribology. This process has been performed by Micro-lapping process. The sapphire crystalline wafers were characterized by double crystal X-ray diffraction. The sample quality of crystalline sapphire wafer at surface has a full width at half maximum of 250 arcsec. This value at the surface sapphire wafer surfaces indicated 0.12${mu}m$ sizes. Surfaces of sapphire wafers were mechanically affected by residual stress and surface default. As a result, the value of surface roughness of sapphire wafers measured by AFM(Atom Force Microscope) was 2.1nm.

• 한국레이저가공학회지
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• 제12권2호
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• pp.7-10
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• 2009

In this paper, we study experimentally the local polishing of $SiO_2$ surface using the $CO_2$ laser. For laser local polishing, we polished to remove the grooves or to be reformed the surface of grooves after forming the grooves on the material surface. We measured the reflectance, transmittance, and beam profile in order to measure the roughness of polished surface. The Atom Force Microscope (AFM) is used to measure roughness of local polishing surface. We can predict that the laser polishing contribute to the removal of generated debris and surface roughness on the micro processing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1434-1435
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• 2006

본 연구에서는 polymer gate insulators에 따른 pentacene 유기 박막 트랜지스터 (Organic Thin-Film Transistors)의 전기적 특성을 atom force microscope (AFM), x-ray diffraction (XRD) 그리고 I-V 측정을 이용하여 분석하였다. Pentacene 박막 트랜지스터의 전기적 특성은 pentacene의 증착 조건뿐만 아니라 polymer gate insulator에 따라 크게 영향을 받는다. 따라서 다양한 polymer 기판 위에 온도, 두께 그리고 증착 속도에 따라 pentacene을 증착 하였다. 그리고 증착된 pentacne을 AFM, XRD를 이용하여 pentacene의 구조, 결정화 그리고 grain 크기 등을 분석하였다. 또한 inverted stagger며 구조의 pentacene 박막 트랜지스터 소자를 제작하고 I-V 측정하여 그 결과를 분석하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.232-235
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• 2002

An 150 kV gas cluster ion accelerator was fabricated and assessed. The change of surface morphology and surface roughness were examined by an atom force microscope (AFM) after irradiation of $CO_2$ gas clusters on Si (100) surfaces at the acceleration voltages of 50 kV. The density of hillocks induced by cluster ion impact was gradually increased with the dosage up to 5$\times$10$^{11}$ ions/$\textrm{cm}^2$. At the boundary of the ion dosage of 10$^{12}$ ions/$\textrm{cm}^2$, the density of the induced hillocks was decreased and RMS (root mean square) surface roughness was not deteriorated further. At the dosage of 5x10$^{13}$ ions/$\textrm{cm}^2$, the induced hillocks completely disappeared and the surface became very flat. In addition, the irradiated region was sputtered. $CO_2$ cluster ions are irradiated at the acceleration voltage of 25 kV to remove hillocks on indium tin oxide (ITO) surface and thus to attain highly smooth surfaces. $CO_2$ monomer ions are also bombarded on the ITO surface at the same acceleration voltage to compare sputtering phenomena. From the AFM results, the irradiation of monomer ions make the hillocks sharper and the surfaces rougher On the other hand, the irradiation of $CO_2$ cluster ions reduces the hight of hillocks and planarize the ITO surfaces. From the experiment of isolated cluster ion impact on the Si surfaces, the induced hillocks m high had the surfaces embossed at the lower ion dosages. The surface roughness was slightly increased with the hillock density and the ion dosage. At higher than a critical ion dosage, the induced hillocks were sputtered and the sputtered particles migrated in order to fill valleys among the hillocks. After prolonged irradiation of cluster ions, the irradiated region was very flat and etched.

• Korean Chemical Engineering Research
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• 제43권4호
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• pp.495-502
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• 2005

무전해 도금 용액을 이용하여 구리를 직접 텅스텐(Tungsten, W) 기판 위에 도금하였다. 도금 용액의 농도는 각각 $CuSO_4$ 7.615 g/L, EDTA 10.258 g/L, glyoxylic acid 7 g/L로 하였다. 도금 용액의 pH는 11.0에서 12.8까지 변화시켰으며, 용액의 온도는 $60^{\circ}C$로 유지하였다. 도금된 필름의 특성을 조사하기 위하여 X선 회절분석기, 전계 방출 주사 전자 현미경, 주사형 원자력 현미경, X선 광전자 분석기 및 Rutherford backscattering spectroscope(RBS)를 사용하였다. 구리 도금을 위한 가장 좋은 pH 조건은 11.8이였다. 이 용액에서 10분 동안 도금한 경우 둥근 모양의 구리 입자가 균일하게 도금되었으며, 불순물 peak이 없는 순수 구리 peak이였고, 근평균 제곱 표면 거칠기는 약 11 nm가 되었다. 또한, pH 11.8에서 12분 동안 도금한 필름의 두께는 140 nm이었고 도금속도는 약 12 nm/min였다. 무전해 도금 용액의 pH를 12.8로 증가시키면 도금된 구리 필름은 Cu peak 이외에 불순물 peak인 $Cu_2O$가 나타나고 구리 입자 모양도 기다란 직사각형 모양으로 변하였다. 순수 구리의 도금을 위해서는 도금 용액에서 적당한 pH를 유지하여야 한다. 도금된 구리의 농도는 RBS로 측정한 결과 99 atom％였다. 또한, Cu/W 필름은 전기 도금하는 동안 합금 형태를 이루기 때문에 접착성도 좋았다.