초박막 다공성 알루미나 멤브레인 마스크의 형태적 특성이 졸-겔 증착 방법을 이용한 금속산화물 나노구조물 제작에 미치는 영향 연구

양선아,김병훈,부상돈 한국물리학회 2013 새물리 Vol.63 No.1

Ultrathin porous alumina membranes (UT-PAMs) have been widely used as masks for the fabrication of highly-ordered nanostructures. There are two types of UT-PAMs, attached and connected UT-PAMs, which can be distinguished by the method of preparation. In the case of attached UT-PAMs, an UT-PAM is first grown on aluminum by anodizing an aluminum plate. Then, it is transferred from the aluminum plate to the desired substrate. For connected UT-PAMs, an UT-PAM is prepared directly by anodizing aluminum films deposited on p-type Si substrates. The PZT nanostructures were fabricated by using two kinds of UT-PAMs as masks and a conventional sol-gel method. We found that the shapes of the obtained nanostructures highly depended on the used UT-PAMs. Nanotube arrays and nanodot arrays were obtained when the attached UT-PAM and the connected UT-PAM were used, respectively. These results can be attributed to the different degrees of contact between the UT-PAMs and the substrates. 본 연구에서는 두 가지 유형의 초 박막 다공성 알루미나 멤브레인(ultrathin porous alumina membrane, UT-PAM) 마스크를 제작 하였다. UT-PAM은 만드는 방법에 따라서 attached UT-PAM과 connected UT-PAM로구분되는데, attached UT-PAM은 먼저 양극산화 된 알루미늄 판 위에성장된 UT-PAM을 분리한 후에 그것을 기판 위에 접착(adhesion)하여제작되었으며, connected UT-PAM은 실리콘 기판 위에 알루미늄을 증착시킨 후 바로 양극산화 시켜 제작 되었다. 서로 다른 형태적 특성을지니는 이 두 종류의 UT-PAM을 마스크로 사용하여 PZT나노구조물을제작한 결과 attached UT-PAM을 사용하였을 때에는 제작된 나노구조물이속이 비어있는 형태의 나노튜브 모양을 가지고 잘 배열되어 있는 것을관찰 할 수 있었다. 이와 다르게 connected UT-PAM을 사용하였을 때에는나노튜브 보다는 상대적으로 튜브 안쪽이 차있는 형태의 나노닷 배열제작되는 것을 관찰 하였다. 이와 같이 서로 다른 모양의 나노구조물이형성된 이유는 두 종류 UT-PAM의 기판과의 접착 정도가 다르기 때문으로판단된다.

Fabrication of carbon nanostructures using electron beam lithography and pyrolysis for biosensing applications

이정아(Jung A Lee),이광철(Kwang-Cheol Lee),박세일(Se Il Park),이승섭(Seung S. Lee) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

We present a facile, yet versatile carbon nanofabrication method using electron beam lithography and resist pyrolysis. Various resist nanopatterns were fabricated using a negative electron beam resist, SAL-601, and were then subjected to heat treatment in an inert atmosphere to obtain carbon nanopatterns. Suspended carbon nanostructures were fabricated by wet-etching of an underlying sacrificial oxide layer. Free-standing carbon nanostructures, which contain 122 ㎚-wide, 15 ㎚-thick, and 2 ㎛-long nanobridges, were fabricated by resist pyrolysis and nanomachining processes. Electron beam exposure dose effects on resist thickness and pattern widening were studied. The thickness of the carbon nanostructures was thinned down by etching with oxygen plasma. An electrical biosensor utilizing carbon nanostructures as a conducting channel was studied. Conductance modulations of the carbon device due to streptavidin-biotin binding and pH variations were observed.

얇은 잔존층을 갖는 고분자 나노 구조물의 제작과 응용

조혜성(Hye-Sung Cho),김홍남(Hong-Nam Kim),김재관(Jae-Kwan Kim),서갑양(Kahp-Yang Suh) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

Recently, nanoimprint lithography method has been used to fabricate polymer nanostructures on various substrates such as Si wafer, metal-layer, organic or inorganic materials. Accordingly, the extensive efforts have been made to obtain small polymer nanostructures by using special mold, which having much small size of pattern. Meanwhile, the polymeric residual layer that remains under the nanostructures after process of nanoimprint, is not thin compared with the height of nanostructures. Frequently, polymeric nanostructure is used as barrier in etching process, additional process will be needed to remove the remained residual layer. In this research, we demonstrate very thin residual polymeric layer under nanostructures that leads to direct etching of substrate.

상온저압 나노임프린트 리소그래피 기술

정준호(Jun-ho Jeong),이응숙(Eung-sug Lee) Korean Society for Precision Engineering 2005 한국정밀공학회지 Vol.22 No.2

양극산화를 통해 제작된 TiO₂ 나노튜브 어레이의 분할과 팽창에 따른 안정도 변화 분석

김보현(Bo Hyeon Kim),부상돈(Sang Don Bu) 한국물리학회 2022 새물리 Vol.72 No.11

본 논문에서는 양극산화를 통해 TiO₂ 나노튜브 어레이를 제작하였다. 전계방사형 주사전자현미경을 이용하여 양극산화 시간에 따른 나노튜브 밑부분의 직경에 따른 정렬도 변화를 분석하였다. 양극산화 초기에는 서로 독립적으로 분리된 형태의 TiO₂가 형성된 것을 확인하였다. 이 과정에서, 양극산화 시간이 증가하면서 나노튜브의 팽창과 분열이 진행되는 것을 확인하였다. 큰 직경을 가진 나노튜브가 분할되면서 전체적인 직경의 분포도가 감소하고 그에 따라 나노튜브 형태의 안정성이 향상되는 경향을 보였다. 시간이 더욱 지나면서 나노튜브의 분할이 어느정도 끝나게 되면 나노튜브의 팽창이 더욱 우세하게 진행되어 다시 평균 직경이 증가하는 경향을 보였다. 이러한 결과를 통하여 양극산화의 시간이 정렬도에 영향을 주는 것과 밑부분의 직경이 초반에는 무작위로 생성되는 것을 추가적으로 확인하였다. 또한, TiO₂ 나노튜브가 성장하는 과정에서 밑부분은 성장하며 팽창만 일어나는 것이 아닌 분할 과정이 추가로 있는 것으로 확인되었다. In this research, TiO₂ nanotube arrays were fabricated by using anodization. The change in alignment due to the change in the diameter of the nanotube bottom in accordance with anodization time was analyzed by using field emission scanning electron microscopy. Individually separated TiO₂ was confirmed to have formed in the initial stage of anodization. In this process, the expansion and division of the nanotube proceeded with the prolongation of anodization time. As large-diameter nanotubes divided, the distribution values of the diameters decreased, and the stability degree tended to improve. With the passage of time, when the division of the nanotube had been completed to some extent, the expansion of the nanotube proceeded more predominantly, and the average diameter tended to increase. These findings confirmed that the time of anodization affected the alignment and that the bottom diameter was randomly generated at the beginning. Moreover, during TiO₂ nanotube growth, the bottom part not only expanded but also split.

대칭형 탐침을 이용한 자연모사 나노구조물의 점착력 측정

이학주(Hak-Joo Lee),김재현(Jae-Hyun Kim),조기호(Kiho Cho),한승우(Seung Woo Han),이주영(Joo Young Lee),유영은(Young-Eun Yoo),김완두(Wan-Doo Kim),김경식(Kyung-Shik Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

This paper reports a development of a novel AFM cantilever as a highly sensitive sensor and an application of the cantilever into various mechanical tests for characterizing micro/nano-structures. Using single crystal silicon micromachining techniques, we have designed and fabricated rhombus-shaped symmetric AFM probes. After force-calibration of the cantilever, adhesion test was performed. Adhesive force between silicon tip and Cyclic Olefin Copolymer (COC) nano-fiber arrays was measured using the cantilever with a flat tip. Fiber’s diameter was approximately 200 ㎚. The obtained result exhibited the usual characteristics of force curves of COC nano-fiber arrays, in which a pull-off force was detected at the point of unloading.

IAAL을 통한 다층 3차원 나노 구조물의 제작

이기웅(Kiwoong Lee),최호섭(Hoseop Choi),김대성(Dae Seong Kim),장민석(Min Seok Jang),최만수(Mansoo Choi) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

There have been intense efforts to stack 2D planar nanostructures in order to amplify its photonic functionality or acquire photonic chirality. In this study, we fabricated multi-layer structures layer-by-layer via consecutive execution of e-beam lithography (EBL) and 3D assembly of nanoparticles. Each layer of multi-layer 3D nanostructures is fabricated through 3-step procedures. (1) Patterns on silicon substrate via EBL. (2) Ion assisted aerosol lithography (IAAL) to fabricate 3D nanostructures. (3) Sintering 3D nanostructures by e-beam irradiation to endure the spin-coating of e-beam resistor (ER). Multi-layer 3D nanostructures were manufactured through the repetition of (1) to (3). Then, finally, ER was eradicated through O2 plasma ashing. In addition, after fabricating the multi-layer 3D nanostructures, we compared the surface enhanced Raman spectroscopy (SERS) signals of 3D mono-layer structures with the signals of 3D multi-layer structures. As a result, it was shown that the peak signal intensity of the SERS of the bi-layer nanostructure was twice as high as the monolayer’s.

Phase field crystal 모델을 이용한 마이크로구조물의 멀티스케일 모델링

송지환(Jihwan Song),김동철(Dongchoul Kim) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

Computational modeling of micro- or nanostructure evolution is widely studied in materials engineering field. Phase field approach is a novel approach to simulate the various fields that characterize the micro- and nanostructures. Indeed, many phenomena related with the microstructure evolutions, such as a dendritic growth of materials and spinodal decomposition have been studied using phase field approach. However, the phase field approach has some limitations to model the natural properties arise from their crystalline phases because the phase field represents the fields that are spatially uniform in equilibrium. Recently, the phase field crystal method is proposed to overcome the limits. Moreover the PFC model can consider the phenomena on an atomic length scale and a diffusive time scale in contrast to molecular dynamics which is constrained to evolve at the scale of femtosecond. Here, we introduce the PFC in modeling of microstructure evolution and present a great potential of it.

나노구조물 첨가를 이용한 고온에서의 고체 열전도도 감소

김우철(Woochul Kim),김강민(Kangmin Kim),박준영(Junyoung Park),Suzanne L. Singer,Arun Majumdar,Dmitri Klenov,Arthur C. Gossard,Susanne Stemmer,Joshua M. O. Zide 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

Thermal conductivity of a crystalline solid at high temperature is dominated by the Umklapp process because the number of high frequency phonons increases as with temperature. It is challenging to reduce the thermal conductivity of crystalline solids at high temperature although it is widely known that by increasing the atomic defect concentration, thermal conductivity of crystalline solids can be reduced at low temperature. By increasing the concentration of ErAs nanoparticles in In0.53Ga0.47 As up to 6 atomic percent, we demonstrate a thermal conductivity reduction by almost a factor of three below that of In0.53Ga0.47 As at high temperature. A theoretical model suggests that the mean free path of the low frequency phonons is suppressed by increasing the ErAs nanoparticle concentration.

마이크로/나노 개질된 금속표면을 이용한 방오성능 향상

송경환(Kyounghwan Song),심재환(Jaehwan Shim),정정열(Jung-Yeul Jung),이충엽(Choongyeop Lee),남영석(Youngsuk Nam) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

In this work, we investigated the anti-fouling behaviors of titanium surface by varying the wetting morphology. We nanostructured titanium surfaces by applying hot alkali solution, which turned the surfaces into superhydrophilic. Then a silane was vapor-deposition on the surface to induce superhydrophobicity. Using the fluorescence image analysis, anti-fouling performance were extracted from the samples with different wetting morphologies, and their anti-fouling performance was quantitatively compared with that of untreated titanium sample. The results show that investigated superhydrphilic surface can improve the anti-fouling performance by approximately 90% in 12h. When the superhydrophobicity was induced after the silane treatment, the sample showed that approximately 80% increase in the anti-fouling performance of 48h. When the oil was infused on superhydrophobic surface, the sample showed over 80% increase in the anti-fouling performance in 8~72h. Our work provides the strategies to increase anti-fouling and will help develop titanium surfaces operating at various environment.