• 진공이야기
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• 제2권1호
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• pp.17-20
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• 2015

In this article, a historical and scientific review on the development of an ultrafast electron microscope is supplied, and the challenges in further improvement of time resolution under sub-picosecond or even sub-femtosecond scale is reviewed. By combining conventional scanning electron microscope and femtosecond laser technique, an ultrafast electron microscope was invented. To overcome its temporal resolution limit which originates from chromatic aberration and Coulomb repulsion between individual electrons, a generation of electron pulse via strong-field photoemission has been investigated thoroughly. Recent studies reveal that the field enhancement and field accumulation associated with the near-field formation at sharply etched metal nanoprobe enabled such field emission by ordinary femtosecond laser irradiation. Moreover, a considerable acceleration reaching 20 eV with near-infrared laser and up to 300 eV acceleration with mid-infrared laser was observed, and the possibility to control the amount of acceleration by varying the incident laser pulse intensity and wavelength. Such findings are noteworthy because of the possibility of realizing a sub-femtosecond, few nanometer imaging of nanostructured sample.in silicon as thermoelectric materials.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1017-1020
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• 2004

It is not efficient and scarcely out of the question to use commercial expensive electron beam lithography system widely used for semiconductor fabrication process for the manufacturing application field of various devices in the small business scope. Then scanning electron microscope based electron beam machining system is maybe regarded as a powerful model can be used for it simply. To get a complete suite of thus proper system, column unit build up with several electo-magnetic lens is necessarily required more than anything else to modify scanning electron microscope. In this study, various components included several electro-magnetic lens and main body which are essentially constructed for column unit are designed and manufactured. And this established column unit will be used for next connected study in the development step of scanning electron microscope based electron beam machining system.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.892-898
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• 2013

A field emission projection microscope was constructed to investigate the atomic and chemical-bonding structure of molecules using electron in-line holography. Fringes of carbon nanotube images were found to be interferograms equivalent to those created by the electron biprism in conventional electron microscopy. By exploiting carbon nanotubes as the filament of the electron biprism, we measured the transverse coherence length of the electron beam from tungsten field emitters. The measurements revealed that a partially coherent electron-beam was emitted from a finite area.

• 식물조직배양학회지
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• 제22권6호
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• pp.323-327
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• 1995

미나리의 체세포 배발생 과정을 해부학적으로 구명하기 위하여 배발생 기원세포와 캘러스를 광학현미경 및 전자현미경으로 관찰한 결과, 배발생 세포는 hematoxylin에 짙은 보라색으로, 비배발생 세포는 safranin에 적색으로 염색되어 광학현미경하에서 쉽게 구별할 수 있었다. 배발생 캘러스는 많은 수의 원배 및 발육중인 배, 비배발생 세포 등으로 구성되어 있었다. 체세포 배발생은 발육 중인 배나 세포괴의 표피세포에 위치한 배발생 세포의 하나가 분열하거나 세포괴내의 비배발생 세포속에 묻혀 있는 배발생 세포가 분열하여 일어났다. 배발생 과정은 항상 일정한 형태는 아니지만 단세포로부터 일정한 segmentation 과정를 거쳐서 배발생이 진행되는 것으로 나타났다. 투과전자현미경에 의한 관찰에서 배발생 세포는 비배발생 세포에 비하여 세포질이 조밀하고 핵이 대형이며 amyloplast, 인지질체 및 세포소기 관들이 많으며 액포가 없거나 매우 작았다. 이들 세포들은 두터운 세포벽에 의하여 주위의 비배발생 세포와 분리되어 있으며 세포윤곽은 둥글었다. 주사전자현미경으로 관찰한 배발생캘러스는 외부가 그물이 씌워진 형태의 구형의 다양한 크기의 배들과 비교적 크기가 큰 비배발생 세포들이 혼재하였다. 한편 비배발생능 캘러스는 구성세포가 크고 외부에는 gelatin같은 물질로 덮여 있었다.

• Applied Microscopy
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• 제51권
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• pp.1.1-1.2
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• 2021

We demonstrate a fabrication of an atomically controlled single-crystal heart-shaped nanostructure using a convergent electron beam in a scanning transmission electron microscope. The delicately controlled e-beam enable epitaxial crystallization of perovskite oxide LaAlO₃ grown out of the relative conductive interface (i.e. 2 dimensional electron gas) between amorphous LaAlO₃/crystalline SrTiO₃.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1271-1276
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• 2007

The most powerful analytical equipment usually comes at the cost of having the highest demand for space. Where electron microscopes has traditionally required a room to themselves, not just for reasons of their size but because of ancillary demands for pipes and service. The simple optical microscopes, of course, can occupy the desk-top, but because their performance is limited by the wavelength of light, their powers of magnification and resolution are inferior to that of the electron microscope. Mini SEM will sit comfortably on a desk-top but offers magnification and resolution performances much closer to that of a standard SEM. This new technique extends the scope of SEM as a high-resolution microscope, relatively cheap and widely available imaging tool, for a wider variety of samples.

• 환경위생공학
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• 제1권1호
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• pp.31-40
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• 1986

It was observed by electron microscope (transmission electron microscope, Scanning electron microscope) as a study on microstructure of soybean after r-ray irradiation with the intensity of 5KGY, 7KGY, 10KGY and 15KGY, fermented with the named Bacillus subtilis SCF, which newly separated and identified. According to the progress fermentation, changes of soybean microstructure have been increased, especially irradiated soybeans more increased than non-irradiated them. Observation of microstructure by electron microscope showed that each protein body became more. expanded in the dimension and decomposed, spherosome around the protein body in unit area dispersed and dwindled in the numbers of it. As the fermentation on progress, changes of soybean microstructure were suitable on fermentation period of 7KGY soybean, 48-72hrs fermentation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.132-134
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• 2006

To improve equipment throughput and device yield, a malfunction in plasma equipment should be accurately diagnosed. A recognition model for plasma diagnosis was constructed by applying neural network to scanning electron microscope (SEM) image of plasma-etched patterns. The experimental data were collected from a plasma etching of tungsten thin films. Faults in plasma were generated by simulating a variation in process parameters. Feature vectors were obtained by applying direct and wavelet techniques to SEM Images. The wavelet techniques generated three feature vectors composed of detailed components. The diagnosis models constructed were evaluated in terms of the recognition accuracy. The direct technique yielded much smaller recognition accuracy with respect to the wavelet technique. The improvement was about 82%. This demonstrates that the direct method is more effective in constructing a neural network model of SEM profile information.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.427-428
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• 2008

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2005년도 제36차 추계학술대회 및 제4회 HVEM 이용자 워크샵
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• pp.150-152
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• 2005