• 한국전기전자재료학회논문지
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• 제27권7호
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• pp.448-451
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• 2014

Anodic aluminum oxides (AAO) fabricated by the two-step anodizing process have attracted much attention for the fabrication of nano template because of pore structure with high aspect ratio, low cost process and ease of fabrication. AAOs are characterized by a homogeneous morphology of parallel pores that grow perpendicular to the template surface with a narrow distribution of diameter, length and inter-pores spacing, all of which can be easily controlled by suitably choosing of the anodizing parameters such as pH of the electrolyte, anodizing voltage and duration of anodizing. In this study, AAO templates were characterized by X-ray diffraction and field-emission scanning electron microscope (FE-SEM). The dependence of the pore size change according to the amount of addition of phosphoric acid, which was used to remove the initial alumina oxide layer, was not observed.

• 한국재료학회지
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• 제14권9호
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• pp.664-669
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• 2004

Anodic aluminum oxide (AAO) with pores of various diameter, density, and thickness values was obtained through control of the anodization parameters including voltage, temperature, pore widening time, anodization time, etc. The pore diameter was controlled by a pore widening in an etchant, and alumina templates having stepped nano-channels were fabricated by repetition of anodization and pore widening processes. Stepped carbon nanotubes (CNTs) were then grown on the stepped AAO templates by pyrolysis of acetylene without using the catalyst. High-resolution transmission electron microscopy images revealed that CNTs have a multi-wall structure made of graphite flakes of several nm sizes. The current-voltage characteristic of the sloped and linear CNTs were also examined.

• 한국분말재료학회지
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• 제22권3호
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• pp.216-220
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• 2015

Vertically oriented nickel nanowire arrays with a different diameter and length are synthesized in porous anodic aluminium oxide templates by an electrodeposition method. The pore diameters of the templates are adjusted by controlling the anodization conditions and then they are utilized as templates to grow nickel nanowire arrays. The nickel nanowires have the average diameters of approximately 25 and 260 nm and the crystal structure, morphology and microstructure of the nanowires are systematically investigated using XRD, FE-SEM and TEM analysis. The nickel nanowire arrays show a magnetic anisotropy with the easy axis parallel to the nanowires and the coercivity and remanence enhance with decreasing a wire diameter and increasing a wire length.

• 공업화학
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• 제20권6호
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• pp.586-592
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• 2009

나노 크기의 배향성을 갖는 구조물의 제작은 자연에 존재하는 여러 가지 형상의 모방을 가능하게 한다. 고분자는 가격이 매우 저렴하며 합성과 가공 그리고 그 구조가 잘 알려져 있는 장점을 갖고 있어 필름(film)의 표면에 이러한 나노 구조물을 제작하고 나노 구조의 특성을 발현하는데 손쉽게 활용할 수 있는 재료이다. 나노 구조물을 제작하는 방법 중 양극산화를 통하여 제작한 다공성 알루미나 템플레이트(porous alumina template)는 매우 규칙적으로 정렬되어 있고 제어하는 공정이 비교적 쉽고 경제적이기 때문에 이를 이용한 연구가 매우 활발하게 진행되고 있다. 본 총설에서는 양극산화 알루미나 템플레이트의 제작과 이를 이용한 나노 구조 고분자 필름의 제작을 설명하고 이러한 나노 구조 필름의 응용범위 및 응용에 필요한 특성에 대하여 기술하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.120-122
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• 2005

An alumina membrane with nano-sized pore array by anodic oxidation using thin film aluminum deposited on silicon wafer was fabricated. It is important that the sample prepared by metal deposition method has a flat aluminum surface and a good adhesion between the silicon wafer and the thin film aluminum. The oxidation time was controlled by observation of current variation. While the oxalic acid with 0.2M was used for low voltage anodization under 100V, the chromic acid with 0.1M was used for high voltage anodization over 100V. The nano-sized pores with diameter of 60~120nm was obtained by low voltage anodization of 40~90V and those of 200~300nm was obtained by high voltage anodization of 120~160V. Finally, the sample was immersed to the phosphoric acid with 0.1M concentration to etching the barrier layer. The sample will be applied to electronic sensors, field emission display, and template for nano-structure.

• 한국재료학회지
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• 제14권2호
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• pp.133-140
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• 2004

We carried out anodic aluminum oxide (AAO) on a Si and a sapphire substrate. For anodic oxidation of Al two types of specimens prepared were Al(0.5 $\mu\textrm{m}$)!Si and Al(0.5 $\mu\textrm{m}$)/Ti(0.1 $\mu\textrm{m}$)$SiO_2$(0.1 $\mu\textrm{m}$)/GaN(2 $\mu\textrm{m}$)/Sapphire. Surface morphology of Al film was analyzed depending on the deposition methods such as sputtering, thermal evaporation, and electron beam evaporation. Without conventional electron lithography, we obtained ordered nano-pattern of porous alumina by in- situ process. Electropolishing of Al layer was carried out to improve the surface morphology and evaluated. Two step anodizing was adopted for ordered regular array of AAO formation. The applied electric voltage was 40 V and oxalic acid was used as an electrolyte. The reference electrode was graphite. Through the optimization of process parameters such as electrolyte concentration, temperature, and process time, a regular array of AAO was formed on Si and sapphire substrate. In case of Si substrate the diameter of pore and distance between pores was 50 and 100 nm, respectively. In case of sapphire substrate, the diameter of pore and distance between pores was 40 and 80 nm, respectively

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1495-1496
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• 2011

Anodic aluminum oxide (AAO) nanotemplates for nano electronic device applications have been attracting increasing interest because of ease of fabrication, low cost process, and possible fabrication in large area. The size and density of the nanostructured materials can be controlled by changing the pore diameter and the pole density of AAO nanotemplate. In this paper, AAO nanotemplate was fabricated by second anodization method. In addition, effects of electrolyte and anodization voltate on the microstructure of porous alumina films were investigated. Vertically well aligned pores had the average pore sizes of 15-70 nm and the length of approximately 40 ${\mu}m$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1493-1494
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• 2011

CdS nanostructure materials have been fabricated in porous anodic aluminum oxide (AAO) template by using chemical bath deposition (CBD). These nanostructure materials had uniform diameters of about 15e200 nm, which correspond to the pore sizes of the templates used, and the length was up to 40 mm. X-ray diffraction (XRD) investigation demonstrates that CdS nanostructure materials were hexagonal polycrystalline in nature. As the pore diameter of AAO templates was enlarged, the preferential orientation of c-axis was improved. From PL analysis, the sulfur-deficient defects at the surfaces of CdS nanostructure materials were increasedwhen the samplewas synthesized in the template with larger pore diameter.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.697-700
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• 2002

Porous anodic aluminum oxide(AAO) templates prepared by anodizing method were used for growing multiwalled carbon nanotubes(CNTs). AAO templates with the homogeneous pore diameter and length were obtained by two step anodizing technique. Using AAO templates, vertically well-ordered two-dimensional carbon nanotube arrays were fabricated. We investigated the field emission property of CNTs grown using different catalyst metals in vacuum chamber (<$10^{-7}$ Torr) on AAO Template. To explain the different emission property, the surface reaction between catalysts and alumina pores which inserted carbon species of $C_2H_2$ using High resolution transmission electron microscopy (HRTEM) was studied.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1971-1973
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• 2005

We fabricated an alumina membrane with nano-sized pore array by anodic oxidation using the thin film aluminum deposited on silicon wafer. It is important that the sample prepared by metal deposition method has a flat aluminum surface and a good adhesion between the silicon wafer and the thin film aluminum. The oxidation time was controlled by observation of current variation. The nano-sized pores with diameter of $60{\sim}120nm$ was obtained by $40{\sim}80$ voltage. The pore widening process was employed for obtaining the flat surface because the pores of the alumina membrane prepared by the fixed voltage method shows the structure of rough surface. Finally, the sample was immersed to the phosphoric acid with 0.1M concentration to etching the barrier layer. The sample will be applied to electronic sensors, field emission display, and template for nano- structure.