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차남구;박진구
- Proceedings of the Materials Research Society of Korea Conference
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- 2003.11a
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- pp.72-72
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- 2003
반점착막으로 활용되고 있는 불화유기박막의 형성을 ICP를 이용하여 나노미터로 성장시키고 이를 기계적/화학적 관점에서 특성평가를 수행했다. 증착된 불차유기 박막은 알루미늄 시편위에서 110도 근처를 나타냈으며 30도 근처의 낮은 히스테리시스를 보이는 안정한 박막이 형성되었다. 극성과 비극성 용액을 사용하여 표면에너지를 검사한 결과 약 20 mN/m 이하의 낮은 표면에너지를 얻을 수 있었다. AFM을 이용한 실험결과 표면의 점착력이 약 4nN으로 매우 낮은 점착력을 가짐을 확인 할 수 있었다. FTIR 실험결과 표면에 CF$_2$ 와 같은 불화유기 그룹이 발견되었다.
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김태곤;이수연;박진구;신형재
- Proceedings of the International Microelectronics And Packaging Society Conference
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- 2001.11a
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- pp.226-229
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- 2001
현재 초소형 정밀기계(MEMS;Microelectromechanical System) 소자의 가장 큰 문제점으로 대두되고 있는 점착현상을 방지하기 위하여 불화유기박막을 증착하였다. Octafluorocyclobutane(C$_4$F$_{8}$)을 소스가스를 PECVD (Plasma Enhanced CVD)와 ICP (Inductively Coupled Plasma)를 이용하여 증착하였다. 여기에 Ar을 첨가하여 플라즈마의 반응성을 높여주었다. 형성된 불화유기박막의 나노트라이볼러지 특성을 살펴보기 위하여 AFM을 통하여 증착시킨 시편의 topography를 살펴보았다. 그리고 박막의 antiadhesion의 정도를 살펴보기 위하여 cantilever와 박막의 표면 사이에 존재하는 interaction force를 측정 하였고 AFM의 force curve mode를 이용하였다 PECVB를 이용하여 증착된 박막은 ICP를 이용한 박막보다 균일하지 못한 박막을 보였으며 attractive force가 강한 것으로 사료된다.
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김준성;김태곤;박진구;신형재
- Journal of the Microelectronics and Packaging Society
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- v.8 no.2
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- pp.31-36
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- 2001
Teflon-like fluorocarbon thin film was deposited by using difluoromethane$(CH_2F_2$) added with Ar, $O_2$, and $CH_4$ on Si, $SiO_2$, TEOS, and Al substrate. The deposited thin film was characterized by static contact angles for measuring hydrophobicity in various additive gas ratio. temperature, and working pressure. In case of addition with Ar, the static contact angles decreased as additive gas ratio and power increased. But the static contact angles increased as working pressure increased. Specially, super-hydrophobic surface was obtained using the powder-like fluorocarbon thin film above 2 Torr. Added with $O_2$, the static contact angles decreased as the $O_2$ ratio and working pressure increased. And the static contact angles did not change in 100W, but hydrophilic surface was obtained at 200W. In case of addition of CE$_4$, static contact angles dramatically increased in $CH_4/CH_2F_2$ ratio 5. And continuous static contact angles obtained above ratio 5. As compare with previous experiments by thermal evaporation, the fluorocarbon thin film by plasma polymerization was obtained very low hysteresis. This results shows more homogenous surface by plasma polymerization than thermal evaporation process.
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박진구;차남구;신형재;박장호
- Journal of the Microelectronics and Packaging Society
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- v.6 no.1
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- pp.39-49
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- 1999
Monolayer thick fluorocarbon films were characterized by the contact angle measurements. The contact angles of three different liquids, water, formamide and diiodomethane were measured on spun coated, vapor phased deposited films and Teflon surface. The highest contact angle over $130^{\circ}$was observed on fluorocarbon films deposited on Al substrates while the lowest angles below $70^{\circ}$deposited on oxide. The surface energies were calculated based on Lewis acid /base theory. The surface energies of Teflon and spin coated FC films were calculated to have 18 and 8.4 dynes /cm, respectively. Higher energies of 31 to .35 dynes /cm were calculated on vapor phase deposited films on silicon and oxide. However vapor phase deposited films on aluminum only showed a large Lewis base energy term. It might be explained by the surface roughness and heterogeneity as observed by dynamic contact angles and AFM measurements.
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