• 한국표면공학회지
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• 제50권6호
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• pp.480-485
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• 2017

Soft mold imprinting method that uses nanostructured polymer mold was investigated for anti-reflection film fabrication. The nanostructured soft mold was polyethylene terephthalate(PET) irradiated by oxygen ion beams. The collisional energy transfer between oxygen ion and the polymer surface induced cross-linking and scission reactions, resulting in self-organized nanostructures with regular patterns of the wavenumber of $5{\mu}m^{-1}$. Post processes including ultra-violet curable resin coating and delamination fabricated anti-reflection films. The imprinted resin surface also showed the consistent wavenumber, $5{\mu}m^{-1}$. Pristine PET, oxygen ion beam treated PET, and imprinted replica sample showed total transmittance of 91.04, 93.25, and 93.57-93.88%, respectively.

• 센서학회지
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• 제19권4호
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• pp.259-270
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• 2010

MEMS(micro electro mechanical systems) is a technology for the manufacture hyperfine structure, as a micro-sensor and a driving device, by a variety of materials such as silicon and polymer. Many study for utilizing the MEMS applications have been performed in variety of fields, such as light devices, high frequency equipments, bio-technology, energy applications and other applications. Especially, the field of Bio-MEMS related with bio-technology is very attractive, because it have the potential technology for the miniaturization of the medical diagnosis system. Bio-MEMS, the compound word formed from the words 'Bio-technology' and 'MEMS', is hyperfine devices to analyze biological signals in vitro or in vivo. It is extending the range of its application area, by combination with nano-technology(NT), Information Technology(IT). The LOC(lab-on-a-chip) in Bio-MEMS, the comprehensive measurement system combined with Micro fluidic systems, bio-sensors and bio-materials, is the representative technology for the miniaturization of the medical diagnosis system. Therefore, many researchers around the world are performing research on this area. In this paper, the application, development and market trends of Bio-MEMS are investigated.

• 센서학회지
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• 제17권5호
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• pp.361-368
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• 2008

Nanosized $SnO_2$ particles were synthesized by homogeneous precipitation method using tin chloride ($SnCl_4{\cdot}5H_{2}O$) and urea ($CO(NH_2)_2$). The powders were heated at $500^{\circ}C$ and $600^{\circ}C$ for 2h. The crystal structure, microstructure, thermal behavior, specific surface area were analyzed using XRD, FE-SEM, TGA and BET, respectively. The initial resistance and the $H_2$ sensing properties were measured as a function of ${Sb_2}{O_3}$ and Pd doping concentrations. The resistance was decreased with the addition of ${Sb_2}{O_3}$ and the sensitivity for $H_2$ gas was increased with the addition of Pd. Thus, the optimum $H_2$ gas sensing property was obtained in the 0.25.mol% ${Sb_2}{O_3}$ and 1.w% added $SnO_2$ powders.

• 한국정보통신학회논문지
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• 제6권1호
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• pp.103-108
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• 2002

MOSFET는 전력감소, 도핑농도 증가, 캐리어 속도 증가를 위해서 많은 변화를 가져왔다. 이러한 변화를 받아들이기 위해서, 채널의 길이와 공급전압이 감소해야만하며, 그것으로 인해 소자가 더욱 작아지게 되었다. 현존하고 있는 시뮬레이션 프로그램은 많은 기술자와 과학자들에 의해 개발되어졌다. 본 논문에서는 상용화되어지고 있는 두 가지 시뮬레이터인 Micro-tec과 ISE-TCAD을 사용하여 나노 구조 소자를 시뮬레이션하여 비교하였다. 소자의 게이트 길이(Lg)는 180nm를 사용하였다. 두 시뮬레이터를 사용하여 MOSFET의 특성과 I-V 곡선 및 전계에 대해서 비교 분석하였다.

• 한국군사과학기술학회지
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• 제11권4호
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• pp.83-91
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• 2008

The development of the equal channel angular pressing(ECAP) process in metals has recently provided a feasible solution to produce ultra-fine or nano-grained bulk materials with tailored material properties. However, ECAP process is difficult to scale up commercially due to requirements of an excessive load. In this paper, a new Hybrid-ECAP process with torsional die is considered to obtain materials of ultra-fine grain structure under low forming load. An upper bound analysis and numerical simulation (DEFORM 3D, a commercial FEM code) are carried out on the torsional die. By the upper bound analysis, analytical expression for the compression force and rotation speed are obtained. By the FEM analysis, the distribution of strain, stress and deformation are obtained. These results show that the Hybrid-ECAP is a useful process because this process can obtain the homogeneous deformations with relatively low forming load. Additionally, due to decreased forming load, die life can be improve.

• 한국전기전자재료학회논문지
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• 제33권6호
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• pp.495-499
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• 2020

Power factor improvement at high temperatures has been a major research topic for the development of skutterudite thermoelectric materials. Here, we attempted to optimize the process parameters for manufacturing skutterudite materials, especially for p-type systems. We focused on the effect of aging time variation to maximize the high-temperature performance of the Ce-filled Fe³CoSb¹² skutterudite system. The optimized aging time was concluded to be a key parameter for the formation of single-phase nanostructures in this p-type skutterudite system. The optimized condition was effective in reducing the bipolar effect at high temperature ranges by increasing the carrier concentration in the p-type system. To confirm the conclusions, the electrical conductivity, Seebeck coefficient, and power factor were measured. The results matched well with the microstructure and with those of an XRD analysis performed for the system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1291-1292
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• 2007

Recently, there were many researches for efficiency improvement of DSC. Among of these works, research of surface treatment is still a prerequisite for electron diffusion, light-harvesting and surface state of DSC.[1] Using of the surface treatment, it can be raise up porosity of $TiO_2$ nano-crystalline structure on photo-electrode. There are chemical, physical, electrical and optical methods which raise up its porosity. In this paper, we have designed and manufactured MOPA-type ultrasonic circuit (100W, frequency and duty variable). Manufactured ultrasonic circuit to use to force cavity density and power into $TiO_2$ paste. Then, we have optimized forcing time, frequency and duty of ultrasonic irradiation for surface treatment of photo-electrode of DSC. In I-V characteristic test of DSC, ultrasonic and thermal treated DSC shows 19% improved its efficiency against monolithic DSC. And it shows stability of light-harvesting from drastically change of light irradiation test.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.306-306
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• 2007

The surface was transformed to porous titanium oxide by the anodization of pure titanium. Titanium was anodized in non-aqueous and aqueous electrolytes at different potentials between 5 V and 150 V. Various electrolytes were compose of ethylene glycerol, $H_2SO_4,\;NH_4F\;and\;H_2O$. We obtained titania nanotube arrays on the micro pore of titanium. Micro pores and nano tubes were obtained by anodization at high potentials and low potentials, respectively. Morphologies of nanotubes and micro pore were characterized by FE-SEM. The unique surface structure is very attractive to electrical and medical applications such as gas sensor, biosensor, dental implant and stent.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.95-96
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• 2005

나노 구조 제작을 위한 다양한 시도 중 블록 공중합체를 이용한 방법은 현재 활발한 연구가 진행되고 있는 분야이다. 본 연구에서는 비휘발성 메모리 소자의 용량 증가를 위하여 블록 공중합체 박막을 나노 마스크로 이용하고, 평행판헝 반응관 내에서 반응성 이온 에칭을 사용하여 나노 구조의 표면을 제작하였다. 에칭동안에 나노 마스크로서 사용할 블록 공중합체 박막은 PS-b-PMMA를 이용하여 제작하였고, UV를 주사하여 PMMA를 제거하고 수직적인 나노 흩을 구성하여 나노 패터닝이 가능하도록 하였다. 실험을 통하여 매우 균일한 나노 바늘 형태의 구조를 생성할 수 있으며, 반응기체와 유량의 조절을 통하여 다양한 표면 구조를 확인할 수 있었다. 블록 공중합체는 나노 마스크로서 뛰어난 기능을 나타내며, 이를 이용하여 나노 사이즈의 패터닝이 가능하고, 표면적 증가를 통하여 비휘발성 메모리 소자의 용량 증가에 기여할 수 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.78-78
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• 2007

In semiconductor devices, Cu has been used for the formation of multilevel metal interconnects by the damascene technique. Also lower dielectric constant materials is needed for the below 65 nm technology node. However, the low-k materials has porous structure and they can be easily damaged by high down pressure during conventional CMP. Also, Cu surface are vulnerable to have surface scratches by abrasive particles in CMP slurry. In order to overcome these technical difficulties in CMP, electro-chemical mechanical planarization (ECMP) has been introduced. ECMP uses abrasive free electrolyte, soft pad and low down-force. Especially, electrolyte is an important process factor in ECMP. The purpose of this study was to characterize KOH and $KNO_3$ based electrolytes on electro-chemical mechanical. planarization. Also, the effect of additives such as an organic acid and oxidizer on ECMP behavior was investigated. The removal rate and static etch rate were measured to evaluate the effect of electro chemical reaction.