• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.953-956
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• 2005

Low voltage actuation and high isolation characteristics are key features to be solved in electrostatic RF switch design. Since these parameters in the conventional parallel plate MEMS switch design are in trade-off relation, both requirements cannot be met simultaneously. In vertical comb design, however, the actuation voltage is independent to the vertical separation distance between the contact electrodes. Then, we can design the large separation distance between contact electrodes to get high isolation. We have designed an RF MEMS switch which has -40dB isolation at 5 GHz and 6 V operation voltages. The characteristics of the fabricated switch are being evaluate.

• 한국전기전자재료학회논문지
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• 제24권1호
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• pp.64-69
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• 2011

Super-hydrophobic properties have been achieved on the rf-sputtered polytetrafluoroethylene(PTFE) films deposited on etched aluminum surfaces. The microstructural evolution created after etching has been investigated by FESEM. The water contact angle over $160^{\circ}$ can be achieved on the rf-sputtered ultra-tihn PTFE film less than 10 nm coated on aluminum surface etched with 7 wt.%, 12.5 wt.%, and 15 wt.% HCl concentration for 12 min. XPS analysis have revealed the presence of a large quantity of $-CF_3$ and $-CF_2$ groups in the rf-sputtered PTFE films that effectively can reduce the surface energy of etched aluminum. The presence of patterned morphology along with the low surface energy at the rf-sputtered PTFE coating makes the aluminum surface with high super-hydrophobic property.

• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.488-493
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• 2022

Generally, diamond-like carbon films (a-C:H, DLC) have been shown to have a low coefficient of friction, a high hardness and a low wear rate. Pd-doped C thin film was fabricated using a dual magnetron sputtering with two targets of graphite and palladium. Graphite target RF power was fixed and palladium target RF power was varied. The structural, physical, and surface properties of the deposited thin film were investigated, and the correlation among these properties was examined. The doping ratio of Pd increased as the RF power increased, and the surface roughness of the thin film decreased somewhat as the RF power increased. In addition, the hardness value of the thin film increased, and the adhesive strength was improved. It was confirmed that the value of the contact angle indicating the surface energy increases as the RF power increases. It was concluded that the increase in RF power contributed to the improvement of the physical properties of Pd-doped C thin film.

• 한국진공학회지
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• 제21권3호
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• pp.158-163
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• 2012

본 연구에서는 폴리머 애자의 자가세정 코팅을 위한 소재로써 $TiO_2$ 박막을 실리콘과 유리, 폴리머애자 기판위에 증착하였다. $TiO_2$ 박막은 $TiO_2$ 세라믹 타겟이 부착된 RF 마그네트론 스퍼터링 장치를 이용하여 증착하였다. $TiO_2$ 박막은 스퍼터링의 다양한 공정조건 중 RF 파워의 크기에 따라 100 nm의 두께로 증착하였다. RF 파워에 따라 증착되어진 $TiO_2$ 박막의 접촉각, 표면거칠기등 표면 특성을 확인하였으며, UV-visible등 광학적 특성을 고찰하여, 구조적 특성과의 관계를 고찰하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.96-96
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• 2010

To improve surface wettability, each sample was treated by atmospheric pressure plasma (APP) using dielectric barrier discharge (DBD) system. Argon and oxygen gases were used for treatment gas to modify the $TiO_2$ surface by APP with RF power range from 50 to 200 W. Water contact angle was decreased from $20^{\circ}$ to $10^{\circ}$ with argon only. However, water contact angle was decreased from $20^{\circ}$ to < $1^{\circ}$ with mixture of argon and oxygen. Water contact angle with $O_2$ plasma was lower than water contact angle with Ar plasma at the same RF power. It seems to be increasing the polar force of $TiO_2$ surface. Also, analysis result of X-ray photoelectron spectra (XPS) shows the increase of intensity of O1s shoulder peak, resulting in increasing of surface wettability by APP. Moreover, each water contact angle increased according to increase past time. However, contact angle increase with plasma treatment was lower than without plasma treatment. Additionally, the efficiency of $TiO_2$ photocatalyst was improved by plasma surface-treatment through the degradation experiment of phenol

• 한국재료학회지
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• 제16권9호
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• pp.543-549
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• 2006

Polyimides (PI) are treated with $He/O_2$ and $He/O_2/NF_3$ atmospheric pressure rf dielectric barrier discharge in order to investigate the roles of $NF_3$ that is one of the PI etching gases. Surface changes are analyzed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurement. The surface roughness of PI and the ratio of C=O, which is hydrophilic functional group, is more increased by $He/O_2/NF_3$ discharge than by $He/O_2$ discharge. The C=O species on the PI surface is increased up to 30 percent with rf power. The surface roughness of PI is increased from 0.4 to 11 nm with rf power. The water drop contact angles on PI, however, are reduced from $65^{\circ}\;to\;9^{\circ}$ by plasma treatment independently of $NF_3$.

• 한국세라믹학회지
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• 제43권1호
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• pp.38-41
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• 2006

Surface of PC (Polycarbonate) and PES (Polyethersulphone) treated by plasma modification with rf power from 50 W to 200 W substrates in Ar (3 sccm), $O_2$ (12 sccm) atmosphere. From the results of modified substrates in XPS (X-ray Photoelectron Spectroscopy), the ratio of oxide containing bond increased with rf power. As the rf power was 200 W, the contact angle was the lowest value of 14.09 degree. And the datum from AFM (Atomic Force Microscopy), rms roughness value of PES and PC substrates increased with rf power. We could deposit $Ta_2O_5$ with good adhesion on plasma treated PES and PC substrates using by in-situ rf magnetron sputter.

• 한국진공학회지
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• 제19권1호
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• pp.22-27
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• 2010

$TiO_2$의 표면의 친수성을 증가시키기 위하여 dielectric barrier discharge (DBD)에 의해 발생된 대기압 플라즈마 (atmospheric pressure plasma: APP)를 이용 RF power 50~200 W 범위에서 Ar과 $O_2$ 가스를 사용 대기압 플라즈마로 광촉매 표면을 개질하였다. Ar 가스 단독으로 처리한 시료의 접촉각은 20도에서 10도로 감소하였으며, $O_2$ 가스를 반응성 가스로 하여 처리한 경우에는 접촉각이 20도에서 1도 미만으로 감소하였다. 동일한 RF power에서 $O_2$ 플라즈마 처리 시 더 낮은 접촉각을 확인하였는데, 이는 $TiO_2$ 표면과 산소원자의 결합으로 인하여 표면의 polar force의 증가에 의한 것으로 판단되어 대기압 플라즈마로 처리된 시료의 X-ray photoelectron spectroscopy (XPS)의 스펙트럼 분석결과 OH 작용기의 증가로 표면의 친수성이 증가됨을 확인하였다. 대기압 플라즈마로 처리된 시료와 처리하지 않은 시료의 접촉각은 모두 시간이 지남에 따라 증가하지만 플라즈마 처리 된 시료의 접촉각 증가는 플라즈마 처리하지 않은 시료의 접촉각 보다 작은 것을 확인하였다. 또한, 페놀 분해 실험을 통하여 플라즈마 표면처리를 통하여 $TiO_2$ 광촉매의 분해 효율이 크게 향상되는 것을 확인하였다.

• E2M - 전기 전자와 첨단 소재
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• 제8권6호
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• pp.774-779
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• 1995

Process optimization experiments based on the Taguchi method were performed in order to set up the optimal process conditions for the contact oxide etching process module which was built in order to be attached to the cluster system of multi-processing purpose. In order to compare with Taguchi method, the contact oxide etching process carried out with different process parameters(CHF$_{3}$/CF$_{4}$ gas flow rate, chamber pressure, RF power and magnetic field intensity). Optimal etching characteristics were evaluated in terms of etch rate, selectivity, uniformity and etched profile. In this paper, as a final analysis of experimental results the optimal etching characteristics were obtained at the process conditions of CHF3/CF4 gas flow rate = 72/8 sccm, chamber pressure = 50 mTorr, RF power = 500 watts, and magnetic field intensity = 90 gauss.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1306-1308
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• 2003

RF-ID technic will got over not only damage which can be caused by contact ID technic but also worse awareness with the lapse of time. In advance, for subway the fares of mass transportation at rush hours of the days, it's important to find a way to collect fares without unnecessarily delaying passengers. In this paper. we are proposing RF-ID system using the RF Communication Technic and Energy Transformation Technic.