• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.877-880
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• 2008

In this article, in order to fabricate polymer based electrospray device with super hydrophobic nozzle we use PTFE(polyfluorotetraethylene) plate and PMMA(polymethylmethacrylate). To obtain the super hydrophobic surface nozzle, PTFE surface is treated by argon and oxygen plasma treatment process. And evaluate the treated surface, perform measuring contact angle, SEM(Scanning Electron Microscope) and AFM(Atomic Force Microscope). We compare the performance of the super hydrophobic PTFE surface nozzle with raw PTFE and PMMA surface nozzle. For the ion beam treated PTFE nozzle, the liquid doesn't overflow and it keeps initial position and meniscus shape. From these results, we expect in cease of superhydrophobic surface nozzle jetting becomes more stable and repeatable.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.356-356
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• 2007

Plasma immersion ion beam deposition (PIIBD) technique is a cost-effective process for the deposition of diamond like carbon thin film, the possible solid lubricant on large surface and a complex shape. We used PIIB process for the preparation of DLC thin film on $Al_2O_3$ with deposition conditions of deposition temperature range $200^{\circ}C$, working gas pressure of 1.310-1Pa. DLC thin films were coated by $C_2H_2$ ion beam deposition on $Al_2O_3$ after the ion bombardment of SiH4 as the bonding layer. Energetic bombardment of $C_2H_2$ ions during the DLC deposition to ceramic materials generated mixed layers at the DLC-Si interface which enhanced the interface to be highly bonded. Wear test showed that the low coefficient of friction of around 0.05 with normal load 2.9N and proved the advantage of the low energy ion bombardment in PIIBD process which improved the tribological properties of DLC thin film coated alumina ceramic. Furthermore, PIIBD was recognized as a useful surface modification technique for the deposition of DLC thin film on the irregular shape components, such as molds, and for the improvement of wear and adhesion problems of the DLC thin film, high temperature solid lubricant.

• 한국재료학회지
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• 제15권7호
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• pp.458-464
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• 2005

In microelectronics packaging, the reliability of the metal/polymer interfaces is an important issue because the adhesion strength between dissimilar materials is often inherently poor. The modification of polymer surfaces by ion beam irradiation and rf plasma is commonly used to enhance the adhesion strength of the interface. T-peel strengths were measured using a Cu/polyimide system under varying $N_2^+$ ion beam irradiation conditions for pretreatment. The measured T-peel strength showed reversed camel back shape regarding the fixed metal-layer thickness, which was quite different from the results of the 90° peel test. The elementary analysis suggests that the variation of the T-peel strength is a combined outcome of the plastic bending work of the metal and polymer strips. The results indicate that the peel strength increases with $N_2^+$ ion beam irradiation energy at the fixed metal-layer thickness.

• 한국재료학회지
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• 제15권1호
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• pp.42-46
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• 2005

In microelectronics packaging, the reliability of the metal/polymer interfaces is an important issue because the adhesion strength between dissimilar materials is often inherently poor. The modification of polymer sufaces by ion beam irradiation and rf plasma are commonly used to enhance the adhesion strength of the interface. T-peel strengths were measured using a Cu/polyimide system under varying $Ar^+$ ion beam irradiation pretreatment conditions. The measured T-peel strength showed reversed camel back shape regarding the fixed metal-layer thickness, which was quite different from the results of the $90^{\circ}$ peel test. The elementary analysis suggests that the variation of the T-peel strength is a combined outcome of the plastic bending work of the metal and polymer strips. The results indicate that the peel strength increases with $Ar^+$ ion beam irradiation energy at the fixed metal-layer thickness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.593-597
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• 2005

FIB equipment can perform sputtering and chemical vapor deposition simultaneously. It is very advantageously used to fabricate a micro structure part having 3D shape because the minimum beam size of ${\phi}$ 10nm and smaller is available. Currently FIB is not being applied in the fabrication of this micro part because of some problems to redeposition and charging effect of the substrate causing reduction of accuracy with regards to shape and productivity. Furthermore, the prediction of the material removal rate information should be required but it has been insufficient for micro part fabrication. The paper have the targets that are FIB-CVD characteristic analysis and minimum line pattern resolution achievement fur 3D micro fabrication. We make conclusions with the analysis of the results of the experiment according to beam current, pattern size and scanning parameters. CVD of 8 pico ampere shows superior CVD yield but CVD of 1318 pico ampere shows the pattern sputtered. And dwell time is dominant parameter relating to CVD yield.

• Nuclear Engineering and Technology
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• 제21권1호
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• pp.40-47
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• 1989

중성입자입사 장치의 효율적인 빔형성 구조를 목적으로 정전기장 내에서 하전 입자의 움직임을 시간의 흐름에 따라 계산해 볼 수 있는 프로그램을 만들어 입자 모사 모형을 찾았다. 가속관 내의 입자의 움직임은 일정 시간 간격으로 계산하였고 전위는 유한차분법에 의해 Poisson 방정식에서 구하였다. 행렬식은 반복해법인 successive overrelaxation법을 사용하였고 전하밀도와 임자에 미치는 전기장의 힘을 구할 때는 cloud-in-cell모델을 사용하였다. 이 전자계산 코드를 사용하여 가속관 내 전극의 여러 조건들을 변화시켜가면서 빔형성 구조의 최적 설계를 수행하였다. 중성자 입사 장치의 가속관에서 가속 감속-전극간의 간격변화, 감속전극의 두께 변화, 가속 전극의 형태변화 등을 통하여 이들이 빔의 모양에 끼치는 영향을 조사하여 몇 가지 경우에 있어서 일정한 시간 간격으로 나타나는 입자들의 움직임을 예시하였다. 이 입자 모사모형을 통하여 가속전극의 형태가 빔 퍼짐에 가장 주요한 역할을 하는 것을 알았다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.231-232
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• 2002

We have been developing microvolume LET counter in order to measure the three-dimensional LET distribution of the therapeutic heavy ion radiation volumes in the water phantom. With help of the technique of cathode induced carhge readout, this detector has a rectangular (box-shape) sensitive volume of which size is about 1 mm$^2$ and 2mm (depth).

• 한국공작기계학회논문집
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• 제15권6호
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• pp.58-63
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• 2006

FIB equipment can perform sputtering and chemical vapor deposition simultaneously. It is very advantageously used to fabricate a micro structure part having 3D shape because the minimum beam size of ${\Phi}10nm$ and smaller is available. Since general FIB uses very short wavelength and extremely high energy, it can directly make a micro structure less than $1{\mu}m$. As a result, FIB has been probability in manufacturing high performance micro devices and high precision micro structures. Until now, FIB has been commonly used as a very powerful tool in the semiconductor industry. It is mainly used for mask repair, device correction, failure analysis, IC error correction, etc. In this paper FIB-Sputtering and FIB-CVD characteristic analysis were carried out according to $Ga^+$ ion beam current that is very important parameter for minimizing the pattern size and maximizing the yield. Also, for FIB-Sputtering burr caused by redeposition of the substrate characteristic analysis was carried out.

• 한국정밀공학회지
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• 제31권3호
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• pp.207-213
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• 2014

A study was carried out to fabricate the cutting tool geometry with micro/nanoscale on the single crystal diamond tool by using the FIB. The FIB technique is an ideal tool for TEM sample preparation that allows for the fabrication of electron-transparent foils. The FIB is appropriate techniques to sample and subsequently define the chemical composition and the structural state of mineral inclusion on the micro/nanoscale. The combination of FIB with a SEM allows for 3D information to be obtained from samples including 3D imaging. Cutting strategies were demonstrated to improve the performance of cutting tool geometry and to generate high aspect ratio micro cutting tool. A finely focused beam of 30keV Ga+ ions was used to mill cutting tool shapes for various micro patterns. Therefore FIB sputtering is used to shape a variety of cutting tools with dimensions in the $1-5{\mu}m$ range and cutting edge radii of curvature of under 50nm.

• Current Optics and Photonics
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• 제5권5호
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• pp.576-582
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• 2021

Dichroic beam-splitter (DBS) with polarization-maintaining took an important role in the free space quantum telecommunication tests on the Micius satellite of China. In this presentation, we designed and prepared a 50 layer polarization-maintaining DBS coating by a dual ion beam sputtering deposition (Dual-IBS) method. In order to solve a stress problem, an 18 layer special anti-reflection (AR) coating with similar physical thickness ratio was deposited on the backside. By stress compensation, the surface flatness RMS value of the DBS sample decreased from 0.341 λ (@632.8 nm) to 0.103 λ while beam splitting and polarization maintaining properties were almost kept unchanged. Further, we discussed the mechanism of film stress and stress compensation by equation deduction and found that total stress had a strong relationship with the total physical thickness and the ratio of layer materials.