• 한국표면공학회지
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• 제44권4호
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• pp.155-164
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• 2011

Electron beam evaporation source is widely used to prepare thin films by physical vapor deposition because it is very effective to vaporize materials and there is virtually no limit to vaporize materials including metals and compounds such as oxide. In this study, evaporation characteristics of various metals and compounds from an electron beam evaporation source have been studied. The 180 degree deflection type electron beam evaporation source which has 6-hearth crucibles and is capable of inputting power up to 10 kW was employed for evaporation experiment. 36 materials including metals, oxides and fluorides have been tested and described in terms of optimum crucible liner, evaporation state, stability, and so on. Various crucible liners have been tried to find out the most effective way to vaporize materials. Two types of crucible liners have been employed in this experiment. One is contact type liner, and the other is non-contact type one. It has been tried to give the objective information and the most effective evaporation method on the evaporation of materials from the electron beam evaporation source. It is concluded that the electron beam evaporation source can be used to prepare good quality films by choosing the appropriate crucible liner.

• 방사선산업학회지
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• 제5권4호
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• pp.297-303
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• 2011

The purpose of this research is to detect whether agricultural products were electron beam irradiated or non-irradiated by chemical methods according to increase of storage period. The three fat-rich samples including soybean, walnut, and sesame were chosen as agricultural products, and then were irradiated with doses of 1~10 kGy by using 10 MeV electron beam facility. At the result, 8-heptadecene and 1,7-hexadecadiene, which are indicators of electron beam-irradiation in chemical methods by gas chromatography/mass spectrometry(GC/MS) method, were detected in all three samples. The levels of two irradiation indicators were increased by electron beam-irradiation in a dose-dependent manner. Furthermore, two irradiation indicators also were detected in all samples in 6 and 12 months after irradiation, though levels of those were decreased in a time-dependent manner. These results mean that the quantification of 8-heptadecene and 1,7-hexadecadiene could determine whether electron beam were irradiated or non-irradiated until 12 month after irradiation in 3 fat-rich agricultural products including soybean, walnut, and sesame.

• 펄프종이기술
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• 제46권4호
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• pp.37-43
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• 2014

The crystallinity and molecular weight of cotton linter need to be controlled to be more easily dissolved in NMMO during manufacture of clothing fabrics. Electron beam irradiation and sulfuric acid treatment were used as pre-treatment to reduce molecular weight of cotton linter more efficiently, and after the pre-treatment, peroxide bleaching was followed in alkaline condition. After those processes, the crystalline indices of the cotton linters were measured by XRD method, and other properties such as their alpha cellulose contents and degree of polymerization were measured. It was found that the crystallinity index of cotton linter was decreased as the irradiation of electron beam increased while increased as the dose of sulfuric acid increased. These results strongly suggested that electron beam damaged the crystalline structure of the cellulose directly while sulfuric acid dissolved mostly non-crystalline area of the cellulose structure.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.743-747
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• 2007

반도체 소자 제작에 있어서 회로의 pattern 형성에 이용하는 차세대 lithography 공정 기술을 위해서 전자빔 lithography 공정 기술 연구가 진행되고 있다. 본 연구에서는 Gauss 해석법과 Monte Carlo의 수치해석법을 사용하여 두께 100 nm의 PMMA (poly-methyl-methacrylate) resist에 전자 $1{\times}10^4$를 입사시키고, 입사 전자빔 에너지에 따른 PMMA 내에서의 투과 깊이를 비교하였다. 전자빔 에너지의 크기는 100eV, 300eV, 500eV, 700eV, 그리고 1000eV에 대하여 simulation을 실시하였다.

• 한국인쇄학회지
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• 제20권1호
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• pp.102-112
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• 2002

Cathode ray tubes (CRT) are the most common electronic display in use in information technology. The CRT consists of an electron gun, electrostatic or magnetic fields to direct the electron beam, and a phosphor screen. When the electron beam strikes the phosphor screen, the phosphor generates light. The phosphor screen has formed by precipitation method, electro-forming and centrifuge method. The high quality product was achieved by electro-forming or centrifuge method. Now applying method is electro-forming used with phosphor and Eh(isopropyl alcohol). Now applying method has been much consumption of raw-material, dirty working environment, dangerous fire and require of high cost. New method to form phosphor surface of monochrome is required to improve this matter. This study was developed novel method to form the phosphor surface by heat-transfer method. This method have advantages of simple process, automatization, clean environment, saving raw material and saving running-cost.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4678-4684
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• 2023

Using the Monte Carlo method, the impact of the angular distribution of the electron source on the dose distribution for the 2.5 MeV ELV electron accelerator was explored. The experiment measured the 3-D dose distribution in the irradiation chamber for electron energies of 1.0 MeV and 2.5 MeV. The simulation used the MCNP6.2 code to evaluate three angular distribution models of the source: a mono-directional beam, a cone shape, and a triangular shape. Of the three models, the triangular shape with angles θ = 30°, φ = 0° best represents the angle of the scan hood through which the electron beam exits. The MCNP6.2 simulation results demonstrated that the triangular model is the most accurate representation of the angular distribution of the electron source for the 2.5 MeV ELV electron accelerator.

• 방사선산업학회지
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• 제4권3호
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• pp.271-276
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• 2010

Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1741-1744
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• 2005

The electron beam machining provides very high resolution up to nanometer scale, hence the E-Beam writing technology is rapidly growing in MEMS and nano-engineering areas. For E-Beam machining, $2^{nd}$ electron detector is required to see a machined sample at the stage. The $2^{nd}$ electron detector is composed of scintillator and photomultiplier with signal amplifier and high voltage power supplier. Since a photomultiplier tube is an extremely high-sensitivity photodetector, the signal light level to be detected is very low and therefore particular care must be exercised in shielding external light. In this paper, the design methodology of $2^{nd}$ electron detector and the image noise removal method are introduced.

• Applied Microscopy
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• 제39권1호
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• pp.79-83
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• 2009

We report a useful method to estimate the electron dose rate which may be a decisive factor to characterize sample properties. Even though most mircoscopes have their own exposure meters, there are several practical concerns when such exposure meters are used to measure the electron dose rate: 1) Specimen should be avoided within the entire area of exposure meter; 2) beam current has to be always recorded whenever the operation mode is changed; 3) the electron dose rate can not be calculated for the beam current beyond the detectable range. To overcome these limitations, we suggest a useful method which utilize a CCD (charge coupled device) camera which is now a popular detector to obtain the final electron micrographs. We have evaluated the CCD sensitivity using the linear relationship between electron current on the exposure meter and counter ratio on the CCD camera which are built in KBSI-HVEM (high voltage electron microscope). Applying the new method, we obtained the CCD sensitivity which are approximately 0.039 counts/$e^-$ and 1.37 counts/$e^-$ for the Top-TV and the HV-GIF CCD cameras, respectively.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권6호
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• pp.617-621
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• 2013

This study examined the effect of electron-beam (E-beam) irradiation on the electrical properties of n-GaN, AlGaN and AlGN/GaN structures on sapphire substrates. E-beam irradiation resulted in a significant decrease in the gate leakage current of the n-GaN, AlGaN and HEMT structure from $4.0{\times}10^{-4}A$, $6.5{\times}10^{-5}A$, $2.7{\times}10^{-8}A$ to $7.7{\times}10^{-5}A$, $7.7{\times}10^{-6}A$, $4.7{\times}10^{-9}A$, respectively, at a drain voltage of -10V. Furthermore, we also investigated the effect of E-beam irradiation on the AlGaN surface in AlGaN/GaN heterostructure high electron mobility transistors(HEMTs). The results showed that the maximum drain current density of the AlGaN/GaN HEMTs with E-beam irradiation was greatly improved, when compared to that of the AlGaN/GaN HEMTs without E-beam irradiation. These results strongly suggest that E-beam irradiation is a promising method to reduce leakage current of AlGaN/GaN HEMTs on sapphire through the neutralization the trap.