• Applied Science and Convergence Technology
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• 제25권6호
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• pp.116-119
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• 2016

In this study, we fabricated the $K^+$ ion source for the various purposes and investigated the emission characteristics. The fabricated $K^+$ ion source was painted in the tungsten filament to make filament type ion source. The RGA spectra show that the filament type $K^+$ ion source has a good out gassing character, so it can be used in the ultra-high vacuum system. The maximum $K^+$ ion current was 20 mA when filament temperature was 1410 K and filament potential was 50 V. When the filament temperature was 1070 K, the initial beam current was 50 mA and decreased only by 2% during 4 hours. The emitting energy was measured to be 2.04 eV. This low value means that the fabricated specimen is a good $K^+$ ion source. We conclude that this filament type ion source can be used in various fields, including the LEIS research.

• 전자공학회논문지A
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• 제32A권8호
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• pp.94-106
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• 1995

A three-dimensional(3D) Monte Carlo simulator for boron ion implantation into <100>single-crystal silicon considering the mask structure has been developed to predict the mask-dependent impurity doping profiles of the implanted boron at low energies into the reduced area according to the trend of a reduction in the size of semiconductor devices. All relevant important parameters during ion implantation have been taken into account in this simulator. These are incident energy, tilt and rotation of wafer, orientation of silicon wafer, presence of native silicon dioxide layer, dose, wafer temperature, ion beam divergence, masking thickness, and size and structure of open window in the mask. The one-dimensional(1D) results obtained by using the 3D simulator have been compared with the SIMS experiments to demonstrate its capabilities and confirem its reliability, and we obtained relatively accurate 1D doping profiles. Through these 3D simulations considering the hole structure and its size, we found the mask effects during boron ion implantation process.

• Journal of Radiation Protection and Research
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• 제40권2호
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• pp.87-91
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• 2015

We have employed X-ray photoelectron spectroscopy (XPS) technique to examine the combined effects of low-energy electron (LEE) irradiation and $Fe^{3+}$ ion on DNA damage. pBR322 plasmid DNA extracted from E. coli ER2420 was used for preparing DNA-$Fe^{3+}$ sample. The C1s XPS spectra were scanned for LEE-irradiated and LEE-unirradiated samples and then curve-fitted. For the samples with LEE irradiation only or with Fe ion only, no significant changes from pure DNA samples were observed - a single effect of either $Fe^{3+}$ ion or LEE irradiation did not cause a significant damage. However, when these two components were combined, the DNA damage was increased quite significantly, compared to the sum of DNA damages caused by $Fe^{3+}$ ion and by LEE irradiation independently. This observation is consistent with our previous results [Radiat. Res. 177, 775 (2012)] which was done using gel-electrophoresis technique. Partial interpretation of the observed spectrum peaks was also attempted.

• 방사선산업학회지
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• 제8권1호
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• pp.59-63
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• 2014

Proton Induced X-ray Emission (PIXE) is a MeV ion beam analysis method for use with particle accelerators. PIXE uses low-energy charged particles as an excitation mechanism to generate characteristic x-ray emission from each element in a target. In PIXE analysis, the beam current used is from a few nA to several tens of nA. Chosun University (Cyclotron Research Center) designed a $50{\mu}A$ beam line from the 13 MeV cyclotron for use with a PIXE analysis system, as well as performing beam transport line optimization research. In this study, the beam line operation conditions for the optimization process of beam transport and beam characteristics are shown.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
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• pp.666-666
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• 2005

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.159-159
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• 2005

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.111-111
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• 2007

Further scaling the semiconductor devices down to low dozens of nanometer needs the extremely shallow depth in junction and the intentional counter-doping in the silicon gate. Conventional ion beam ion implantation has some disadvantages and limitations for the future applications. In order to solve them, therefore, plasma source ion implantation technique has been considered as a promising new method for the high throughputs at low energy and the fabrication of the ultra-shallow junctions. In this paper, we study about the effects of DC bias and base pressure as a process parameter. The diluted mixture gas (5% $PH_3/H_2$) was used as a precursor source and chamber is used for vacuum pressure conditions. After ion doping into the Si wafer(100), the samples were annealed via rapid thermal annealing, of which annealed temperature ranges above the $950^{\circ}C$. The junction depth, calculated at dose level of $1{\times}10^{18}/cm^3$, was measured by secondary ion mass spectroscopy(SIMS) and sheet resistance by contact and non-contact mode. Surface morphology of samples was analyzed by scanning electron microscopy. As a result, we could accomplish the process conditions better than in advance.

• 한국표면공학회지
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• 제24권3호
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• pp.137-143
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• 1991

The relation between the ion irradiation induced grain growth and the basic parameters sinvolved in ion beam mixing process was studied. TEM micrographs showed that a significant grain growth has been induced by Ar+ irradiation at room temperature. The grain size increases rapidly in low dose region, while it approaches a saturated value in high dose region, and it has close relationship with nuclear energy deposition and thermodynamic properties such as cohesive energy ( Hc) and heat of mixing ( Hm). A model for the grain growth based on the thermal spike induced atomic migration was developed and applied to interpret experimental results.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.110-110
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• 1999

Polyvinylidenefluoride (PVDF) is most used in piezoelectric polymer industry. Electrode effect on the electrical properties of PVDF has been investigated. al has been used due to fair adhesion for PVDF. Work function of metal plays an important role on the electrical properties of ferroelectrics for top and /or bottom electrode. However, Al has much lower work function than Pt or Au and so leakage current of Al/PVDF/Al may be large. Pt or Au has not been used for electrode of PVDF system due to poor adhesion. PVDF irradiated by Ar+ ion beam with O2 environment takes good adhesion to inert metal. Contact angle of PVDF to triple distilled water was reduced from 75$^{\circ}$ to 31$^{\circ}$ at 1$\times$1015 Ar+/cm2. Working pressure was 2.3$\times$10-4 Torr and base pressure was 5$\times$10-6 Torr. Pt was deposited by ion beam sputtering and thickness of pt film was about 1000$\AA$. in previous study, enhancing adhesion of Pt on PVDF was shown. in this study, effect of electrode on PVDF will be represented.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.413-416
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• 2004

In this study, zinc oxide(ZnO) having large misfit(18.2%) with sapphire was tried to be grown on very thin nitride buffer layers. For the creation of various kinds of nitride buffer layer, sapphire surface was modified by an irradiation of nitrogen ion beam with low energy generated from stationary plasma thruster(SPT) at room temperature. After the irradiation of ion beam, Al-N and Al-O-N bonding was identified to be formed as nitride buffet layers. Surface morphology was measured by AFM and then ZnO growth was followed by pulsed laser deposition(PLD). Their properties are analyzed by XRD, AFM, TEM, and PL. We observed that surface morphology was improved and deep level emission related to defects was almost vanished in PL spectra from the ZnO grown on nitride buffer layer.