• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.180-180
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• 2005

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.109-109
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• 1999

Recently, low energy ion beam irradiation has been adopted for surface modification. Low energy ion beam irradiation has many advantages in polymer engineering such as weak damage, good adhesion, noticeably-enhanced wettability(less than 15 degree), good reproducibility and so on. In this experiment, chemical reactions between free radicals and environment gas species have been investigated using angle-resolved XPS and TRIM code. In the case of low ion beam energy (around 1 keV), energy loss in polymer is mainly originated from atomic collisions instead of electronic interference. Atomic collisions could generated displaced atoms and free radicals. Cold cathode-ion source equipped with 5cm convex grid was used in an O2 environment. Base and working pressure were 5$\times$10-6 and 2.3$\times$10-4 Torr. Flow rates of argon and oxygen were fixed at 1.2 and 8 sccm. target materials are polyethylene polyvinyidenefluoride and polytetrafluoroethylene.

• Transactions on Electrical and Electronic Materials
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• 제8권1호
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• pp.46-50
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• 2007

We have studied the nematic liquid crystal (NLC) alignment effects on a nitrogen-doped diamond-like carbon (NDLC) thin film layer with ion beam irradiation. The pretilt angle for NLC on the NDLC surface with ion beam exposure was observed below 1 degree. Also, we had the good LC alignment characteristics on the NDLC thin films with ion beam exposure of 1800 eV. In thermal stability experiments, the alignment defect of the NLC on the NDLC surface with ion beam irradiation above annealing temperature of $250^{\circ}C$ can be observed. Therefore, the good thermal stability and LC alignment for NLC by ion beam aligned NDLC thin films can be achieved.

• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.245-249
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• 2007

The liquid crystal display (LCD) applications treated on the organic overcoat thin film surfaces by ion beam irradiation was successfully studied. The good LC aligning capabilities treated on the organic overcoat thin film surfaces with ion beam exposure of $60^{\circ}$ for 2 min above ion beam energy of 1200 eV can be achieved. But, the alignment of defect of NLC on the organic overcoat surface at low energy of 600 eV was measured. The pretilt angle of NLC on the organic overcoat thin film surface with ion beam exposure of $60^{\circ}$ for 2 min at energy of 1800 eV was measured about 1 degree. Finally, the good thermal stability of LC alignment on the organic overcoat thin film surface with ion beam exposure of $60^{\circ}$ for 2 min until annealing temperature of $200^{\circ}C$ can be measured.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.398-398
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• 2007

Most recently, the Liquid Crystal (LC) aligning capabilities achieved by ion beam exposure on the diamond-like carbon (DLC) thin film layer have been successfully studied. The DLC thin films have a high mechanical hardness, a high electrical resistance, optical transparency and chemical inertness. Nitrogen doped Diamond Like Carbon (NDLC) thin films exhibit properties similar to those of the DLC films and better thermal stability than the DLC films because C:N bonding in the NDLC film is stronger against thermal stress than C:H bonding in the DLC thin films. Moreover, our research group has already studied ion beam alignment method using the NDLC thin films. The nematic liquid crystal (NLC) alignment effects treated on the SiNx thin film layers using ion beam irradiation for three kinds of N rations was successfully studied for the first time. The SiNx thin film was deposited by plasma-enhanced chemical vapor deposition (PECVD) and used three kinds of N rations. In order to characterize the films, the atomic force microscopy (AFM) image was observed. The good LC aligning capabilities treated on the SiNx thin film with ion beam exposure for all N rations can be achieved. The low pretilt angles for a NLC treated on the SiNx thin film with ion beam irradiation were measure.

• 한국재료학회지
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• 제16권6호
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• pp.367-372
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• 2006

Polytetrafluoroethylene (PTFE) surface was modified for improving hydrophilicity by ion irradiation in environmental gas of $N_2$ and $NH_3$, respectively. The water contact angle onto the PTFE surface increased from $104{\circ}$ to over $140{\circ}$ by Ar ion irradiation in $N_2$ gas. In the case of $NH_3$ as environmental gas, there were a slight increase of contact angle from ion dose of $1{\times}10^{15}\;to\;5{\times}10^{15}\;ions/cm^2$, and its dramatic decrease to the value of 35o at the conditions of ion dose higher than $1{\times}10^{16}\;ions/cm^2$. It was found from SEM results that the surface morphology of PTFE was changed into one with filament structure after Ar ion irradiation in $N_2$ gas environments. On the contrary, Ar ion irradiation in $NH_3$ gas condition induced the PTFE surface with network structure. Hydrogen ion irradiation resulted in a little change of PTFE surface morphology, comparing with the case of Ar ion irradiation. The water contact angle of hydrogen ion irradiated PTFE surface in reactive gas decreased with increment of ion dose. Hydrogen ion irradiation could improve hydrophilicity with little change of surface morphology. It might be considered from FT-IR results that the improvement in wettability of PTFE surface by ion irradiation in $N_2$ and $NH_3$ gases could be due to the hydrophilic groups of NHx bonds.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1155-1158
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• 2004

Various inorganic alignment layers of nematic liquid crystal (NLC) molecules were investigated. Ar ion beam (IB) irradiation was utilized for alignment method and homogenous and homeotropic orientations with tilt angle were obtained on the suitable inorganic thin films. Proper doping materials were added to diamond-like carbon (DLC) films. In the case of homogeneous alignment, nitrogen doping affected the increase of pretilt angle, while the fluorine bonding in the DLC films was induced the tilted homeotropic alignment cause its extreme hydrophobic property. These results showed that ion beam irradiation method could be applied to the various alignment mode of NLC such as IPS, TN and MVA.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.75-78
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• 2005

Using a low-energy Ar+ ion-beam with and without reactive gases, polymers such as chemically stable poly(ether ether ketone) (PTFE) and poly(ether ether ketone) (PEEK) films were modified to have special surface features. The adhesion strength between the polymers and the copper was significantly improved because of both changes in the surface topography and chemical interactions due to polymer surface functionalization (oxidation and amination). The surface modification altered the failure mode from adhesive failure for the unmodified polymer/Cu interface to cohesive failure for the surface-modified polymer/Cu layer interface..

• 폴리머
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• 제37권4호
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• pp.431-436
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• 2013

폴리카보네이트(PC) 필름에 이온 조사량과 에너지를 변화시켜 가면서 여러 종류의 이온을 조사하였다. 광 투과 특성과 화학적 조성은 각각 UV-VIS와 FTIR(ATR) spectroscopy를 이용해서 얻었다. 400 nm에서 이러한 UV-A 차단율은 에너지와 이온 조사량에 따라서 10에서 100%까지 자유롭게 조절할 수 있었다. 이온 조사된 PC 필름의 표면 전기 저항은 $10^6-10^{13}{\Omega}/cm^2$까지 전도도의 변화를 보인다. 이온 조사된 필름의 접촉각은 모재 필름의 접촉각보다 감소하였다. 폴리머 표면 형태는 atomic force microscopy(AFM)에 의해서 관찰되었다. 예상대로 더 무거운 Xe 이온 조사 후에 폴리머 필름의 파괴가 더 많았다. 그러나 Ar 이온 조사 후에 폴리머 필름의 표면 거칠기가 더 나타났다. 이것은 Xe 이온 조사의 경우 사용가능한 자유체적의 감소와 관련되어 폴리머 필름 표면층의 강력한 채움으로써 설명될 수 있다.

• 한국표면공학회지
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• 제53권6호
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• pp.280-284
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• 2020

Electron beam irradiation is widely used as a type of surface modification technology to advance surface properties. In this study, the effect of electron beam irradiation on properties, such as surface hardness, wear resistance, roughness, and critical load of Titanium Aluminium nitride (TiAlN) films was investigated. TiAlN films were deposited on the SKD-61 substrate by using cathode arc ion plating. After deposition, the films were bombarded with intense electron beam for 10 minutes. The surface hardness was increased up to 4520 HV at electron irradiation energy of 1500 eV. In addition, surface root mean square (RMS) roughness of the films irradiated at 1500 eV shows the lowest roughness of 484 nm in this study.