• Journal of Electrochemical Science and Technology
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• 제2권4호
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• pp.193-197
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• 2011

The influences of the thickness and microstructure of Fe layer on the electrochemical performances of Fe/Si multilayer thin film anodes were investigated. The Fe/Si multilayer films were prepared by electron beam evaporation, in which Fe layer was deposited with/without simultaneous bombardment of Ar ion. The kinetics of Li insertion/extraction reactions in the early stage are slowed down with increasing the thickness of Fe layer, but such a slowdown seems to be negligible for thin Fe layers less than about $500{\AA}$. When the Fe layer was deposited with ion bombardment, even the $300{\AA}$ thick Fe layer significantly suppress Li diffusion through the Fe layer. This is attributed to the dense microstructure of Fe layer, induced by ion beam assisted deposition (IBAD). It appears that the Fe/Si multilayer films prepared with IBAD show good cyclability compared to the film deposited without IBAD.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1996년도 The 9th KACG Technical Annual Meeting and the 3rd Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.5-18
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• 1996

The solid state cesium ion source os alumino-silicate based zeolite which contains cerium. The material is an ionic conductor. Cesiums are stably stored in the material and one can extract the cesiums by applying electric field across the electrolyte. Cesium ion bombardment has the unique property of producing high negative ion yield. This ion source is used as the primary source for the production of a negative ion without any gas discharge or the need for a carrier gas. The deposition of materials as an ionic species in the energy range of 1.0 to 300eV is recently recognized as a very promising new thin film technique. This energetic non-thermal equilibrium deposition process produces films by “Kinetic Bonding / Energetic Condensation" mechansim not governed by the common place thermo-mechanical reaction. Under these highly non-equilibrium conditions meta-stable materials are realized and the negative ion is considered to be an optimum paeticle or tool for the purpose. This process differs fundamentally from the conventional ion beam assisted deposition (IBAD) technique such that the ion beam energy transfer to the deposition process is directly coupled the process. Since cesium ion beam sputter deposition process is forming materials with high kinetic energy of metal ion beams, the process provider following unique advantages:(1) to synthesize non thermal-equilibrium materials, (2) to form materials at lower processing temperature than used for conventional chemical of physical vapor deposition, (3) to deposit very uniform, dense, and good adhesive films (4) to make higher doposition rate, (5) to control the ion flux and ion energy independently. Solid state cesium ion beam sputter deposition system has been developed. This source is capable of producing variety of metal ion beams such as C, Si, W, Ta, Mo, Al, Au, Ag, Cr etc. Using this deposition system, several researches have been performed. (1) To produce superior quality amorphous diamond films (2) to produce carbon nitirde hard coatings(Carbon nitride is a new material whose hardness is comparable to the diamond and also has a very high thermal stability.) (3) to produce cesiated amorphous diamond thin film coated Si surface exhibiting negative electron affinity characteristics. In this presentation, the principles of solid state cesium ion beam sputter deposition and several applications of negative metal ion source will be introduced.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.119-119
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• 2015

Ion beam sputtering has been widely used in Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS), and Auger Electron Spectroscopy (AES) for depth profile or surface cleaning. However, mainly due to severe matrix effects such as surface composition change from its original composition and damage of the surface generated by ion beam bombardment, conventional sputtering skills using mono-atomic primary ions with energy ranging from a few hundred to a thousand volts are not sufficient for the practical surface analysis of next-generation organic/inorganic device materials characterization. Therefore, minimization of the surface matrix effects caused by the ion beam sputtering is one of the key factors in surface analysis. In this work, the electronic structure of a $Ta_2O_5$ thin film on $SiO_2/Si$ (100) after Ar Gas Cluster Ion Beam (GCIB) sputtering was investigated using X-ray photoemission spectroscopy and compared with those obtained via mono-atomic Ar ion beam sputtering. The Ar ion sputtering had a great deal of influence on the electronic structure of the oxide thin film. Ar GCIB sputtering without sample rotation also affected the electronic structure of the oxide thin film. However, Ar GCIB sputtering during sample rotation did not exhibit any significant transition of the electronic structure of the $Ta_2O_5$ thin films. Our results showed that Ar GCIB can be useful for potential applications of oxide materials with sample rotation.

• 한국표면공학회지
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• 제39권3호
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• pp.105-109
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• 2006

The effects of negative carbon ion beam energy on the bonding configuration, hardness and surface roughness of DLC film prepared by a direct metal ion beam deposition system were investigated. As the negative carbon ion beam energy increased from 25 to 150 eV, the $sp^3$ fraction of DLC films was increased from 32 to 67%, while the surface roughness was decreased. The films prepared at 150 eV showed the more flat surface morphology of the film than that of the film prepared under another ion beam energy conditions. Surface roughness of DLC film varied from 0.62 to 0.22 nm with depositing carbon ion beam energy. Surface nano-hardness increased from 12 to 57 Gpa when increasing the negative carbon ion beam energy from 25 to 150 eV, and then decreased when increasing the ion beam energy from 150 to 200 eV.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권9호
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• pp.527-532
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• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with dc bias voltage of -10V showed lower discharge voltage and lower erosion rate byion bombardment than those samples prepared by conventional magnetron sputtering or E-beam evaporation. The main factor that improves the discharge characteristics by bias voltage is considered to be due to the morphology changes or crystal structure of the MgO thin film by ion bombardement during deposition process.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.234.1-234.1
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• 2015

Molybdenum disulfide (MoS2)는 van der Waals 결합을 통한 층상구조의 물질로써 뛰어난 물리화학적, 기계적 특성으로 Field Effect Transistors (FETs), Photoluminescence, Photo Detectors, Light Emitters 등의 많은 분야에서 연구가 보고 되어지고 있는 차세대 2D-materials이다. 이처럼 MoS2 가 다양한 범위에 응용될 수 있는 이유는 layer 수가 증가함에 따라 1.8 eV의 direct band gap 에서 1.2 eV 의 indirect band-gap으로 특성이 변화할 뿐만 아니라 다양한 고유의 전기적 특성을 지니고 있기 때문이다. 그러나 MoS2 는 원자층 단위의 layer control 이 어렵다는 이유로 다양한 전자소자 응용에 많은 제약이 보고 되어졌다. 본 연구에서는 MoS2 의 layer를 control 하기 위해 ICP system 에서 mesh grid 를 삽입하여 Cl2 radical을 효과적으로 adsorption 시킨 뒤, Ion beam system 에서 Ar+ Ion beam 을 통해 한 층씩 제거하는 방식의 atomic layer etching (ALE) 공정을 진행하였다. ALE 공정시 ion bombardment 에 의한 damage 를 최소화하기 위해 Quadruple Mass Spectrometer (QMS) 를 통한 에너지 분석으로 beam energy 를 20 eV에서 최적화 할 수 있었고, Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy(AFM) 분석을 통해 ALE 공정에 따른 MoS2 layer control 가능 여부를 증명할 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제32권2호
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• pp.262-267
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• 2008

Plasma immersion ion beam (PIIB) nitriding process is an environmentally benign and cost-effective process, and offers the potential of producing high dose of nitrogen ions in a way of simple, fast and economic technique for the high plasma flux treatment of large surface area with nitrogen ion source gas. In this report PIIB nitriding technique was used for nitriding on austenite stainless steel of AISI304 with plasma treatment at $250{\sim}500^{\circ}C$ for 4 hours, and with the working gas pressure of $2.67{\times}10^{-1}$ Pa in vacuum condition. This PIIB process might prove the advantage of the low energy high flux of ion bombardment and enhance the tribological or mechanical properties of austenite stainless steel by nitriding, Furthermore, PIIB showed a useful surface modification technique for the nitriding an irregularly shaped three dimensional workpiece of austenite stainless steel and for the improvement of surface properties of AISI 304, such as hardness and strength

• 한국위성정보통신학회논문지
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• 제9권3호
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• pp.22-26
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• 2014

본 연구에서는 액정의 수직배향을 달성하기 위해서 특별히 제조된 폴리스타일렌 박막에 다양한 이온빔을 조사하는 방법을 사용하였다. 일반적으로 폴리스타일렌 수지는 통상의 폴리이미드 계열의 수지에 비해서 박막코팅을 하였을 때 보다 우수한 투과율을 나타내므로, 투과형 디스플레이로 사용되는 LCD의 배향막 재료로 더 적합하다고 생각되었다. 특히 고휘도이면서 저전력 사양을 달성하여야 하는 휴대용 디스플레이에서의 응용가능성이 기대되었다. 그러나, 일반적인 러빙법에 의한 배향처리에 대해서는 액정분자의 배향성이 폴리이미드 계열의 재료에 비해서 열등하여 사용되지 못하였다. 본 연구에서는 폴리스타일렌 계열의 박막재료를 배향막으로 가공함에 있어서 새로운 이온빔 조사법에 의한 비접촉식 배향법을 사용하였으며, 배향성과 액정분자의 프리틸트각 특성에 대해서 정량적인 결과를 얻을 수 있었다. 실험에서는 폴리스타일렌 수지에 이온빔의 조사시간을 15초까지 변화시키면서 액정분자의 배향성 및 프리틸트각의 특성을 측정하였다. 측정결과 스마트폰 및 휴대용 정보단말기 등의 디스플레이에 적합한 고투과율 액정표시소자의 구현이 가능하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.170-170
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• 2000

Synthetic polymers such as polyimide, polycarbonate, and poly(methyl methacrylate) are long chain molecules which consist of carbon, hydrogen, and heteroatom linked together chemically. Recently, polymer surface can be modified by using a high energy ion beam process. High energy ions are introduced into polymer structure with high velocity and provide a high degree of chemical bonding between molecular chains. In high energy beam process the modified polymers have the highly crosslinked three-dimensionally connected rigid network structure and they showed significant improvements in electrical conductivity, in hardness and in resistance to wear and chemicals. Polyimide films (Kapton, types HN) with thickness of 50~100${\mu}{\textrm}{m}$ were used for investigations. They were treated with two different surface modification techniques: Plasma Source Ion Implantation (PSII) and conventional Ion Implantation. Polyimide films were implanted with different ion species such as Ar+, N+, C+, He+, and O+ with dose from 1 x 1015 to 1 x 1017 ions/cm2. Ion energy was varied from 10keV to 60keV for PSII experiment. Polyimide samples were also implanted with 1 MeV hydrogen, oxygen, nitrogen ions with a dose of 1x1015ions/cm2. This work provides the possibility for inducing conductivity in polyimide films by ion beam bombardment in the keloelectronvolt to megaelectronvolt energy range. The electrical properties of implanted polyimide were determined by four-point probe measurement. Depending on ion energy, doses, and ion type, the surface resistivity of the film is reduced by several orders of magnitude. Ion bombarded layers were characterized by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), XPS, and SEM.

• 한국안광학회지
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• 제9권1호
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• pp.161-166
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• 2004

본 연구에서는 이온빔 증착방법을 사용하여 스테인레스 스틸 기판 위에 TiN 박막을 성장하였다. $10^{-5}$ Torr의 질소 분위기에서 아르곤 가스를 보조 이온빔으로 사용하여 TiN 박막을 성장하였다. TiN 박막의 화학 조성, 색상, 밀착력 등을 En의(원자당 이용에너지) 변화에 따라서 측정하였다. En이 증가 할 때 질소와 Ti의 비율은 선형적으로 변화 하였고, 높은 En의 경우에는 질소와 Ti의 비율은 1.2를 가지며 포화되었다. 밝은 금색은 En이 어떤 임계값(Ecn)에 도달 하였을 때 얻어졌다. 이때의 질소와 Ti의 비율은 0.9 이다.