• 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

• Journal of Information Display
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• 제7권3호
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• pp.1-4
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• 2006

2.22-inch qVGA $(240{\times}320)$ amorphous silicon thin film transistor liquid active matrix crystal display (a-Si TFT-AMLCD) panel has been successfully demonstrated employing a 2.5 um fine-patterning technology by a wet etch process. Higher resolution 2.22-inch qVGA LCD panel with an aperture ratio of 58% can be fabricated as the 2.5 um fine pattern formation technique is integrated with high thermal photo-resist (PR) development. In addition, a novel concept of unique a-Si TFT process architecture, which is advantageous in terms of reliability, was proposed in the fabrication of 2.22-inch qVGA LCD panel. Overall results show that the 2.5 um fine-patterning is a considerably significant technology to obtain higher aperture ratio for higher resolution a-Si TFT-LCD panel realization.

• 한국전기전자재료학회논문지
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• 제11권4호
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• pp.281-287
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• 1998

$BiNbO_4$ ceramics doped with 0.07wt% $V_2O_5$ and 0.03wt% CuO (BNC3V7) were sucessfully sintered at $900^{\circ}C$ through the firing process with Ag electrode. The BNC3V7 shows typically Dielectric constant of 44.3, Thermal Coefficient of resonance Frequency(TCF) of 2 ppm/$^{\circ} and $Qxf_o$ value of 22,000 GHz. The laminated chip Low Pass Filter (LPF) is very sensitive to chip processing parameters, was confirmed by the computer simulation as a function of Q(Quality factors), filter size, capacitor layer thickness, inductor pattern widths. The multilayer type LPF was fabricated by screen-printing with Ag electrode after tape casting and then compared with the simulated characteristics. The results show that characterization of band pass width was similar to that of designed ones.

• 정보저장시스템학회논문집
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• 제9권1호
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• pp.10-16
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• 2013

Through the rapid development of LED TV, a large-area edge-lit backlight unit is widely researched in the display industry for enhancing the optical efficiency, luminous uniformity and slim design. In addition, an edge-lit backlight unit includes many optical sheets such as reflection sheet, prism sheet and diffuser sheet. However the function can be replaced by the carefully patterned light guide plate (LGP). Micro patterns which located on the top and bottom surface of light guide plate was designed by ray-tracing optical simulation. The designed patterns improved the light characteristics of LGP, including optical extraction efficiency and intensity distribution uniformity. These results suggest that it is very effective method to design edge-lit LGP with micro-patterns on both sides for large-area display and to reduce the fabrication cost.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.100-101
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• 2007

Polymer thick film capacitors were successfully fabricated by using ink-jet printing and screen printing technology. First, a bottom electrode was patterned by ink-jet printing of a nano-sized silver ink. Next, a dielectric layer was formed by the screen printing, then a top electrode was pattern by ink-jet printing of a nano-sized silver ink. The printed area of the dielectric layers were changed into $2{\times}2m^2$and $4{\times}2m^2$, and also the area of the electrodes were patterned with $1{\times}1mm^2$ and $1{\times}3mm^2$. The thickness of the printed dielectric layer was ranged from 1.1 to $1.4{\mu}m$. The analysis of capacitances verified that the capacitances was proportional to the area of the printed electrode. The capacitances of the fabricated capacitors resulted in one third of the calculated capacitances.

• 한국정보통신학회논문지
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• 제8권3호
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• pp.535-540
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• 2004

본 논문에서는 CPW급전을 이용한 직사격형 슬롯안테나를 설계 방법에 대해 기술하였다. CPW 급전을 이용한 슬롯안테나는 간단한 구조를 가지고, 능동소자에 집적이 용이하다. 논문에 제시한 안테나는 다중 공진을 이용하여 광대역을 실현하고자 안테나의 구성을 내부패치안테나와 외부패치안테나 두 부분으로 하였다. 또한 안테나의 파라미터 변화와 내부패치 안테나의 위치 및 크기를 변화함으로써 다중공진안테나의 특성을 확인하였다. 제시된 안테나의 각각의 공진주파수 실험 결과치는 1,9GHz, 2.8GHz, 3,5GHz, 4,9GHz로 측정되었다. 각각의 공진주파수의 방사패턴에서 네 번째 공진주파수의 방사패턴이 TM11모드로 나타나므로 실제 제시한 직사각형 슬롯안테나는 3중공진주파수로 나타나는 것을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.90-93
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• 2000

In this study, the rise throughput and the stability in fabrication of device can be obtained by applying of CMP process to STI structure in 0.18um semiconductor device. To employ in STI CMP, the reverse moat process has been added thus the process became complex and the defects were seriously increased. Removal rates of each thin films in STI CMP was not equal hence the devices must to be effected, that is, the damage was occured in the device dimension in the case of excessive CMP process and the nitride film was remained on the device dimension in the case of insufficient CMP process than these defects affect the device characteristics. To resolve these problems, the development of slurry for CMP with high removal rate and high selectivity between each thin films was studied then it can be prevent the reasons of many defects by reasons of many defects by simplification of process that directly apply CMP process to STI structure without the reverse moat pattern process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.573-574
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• 2006

The planarization technology of Chemical-mechanical polishing(CMP), used for the manufacturing of multi-layer various material interconnects for Large-scale Integrated Circuits (LSI), is also readily adaptable as an enabling technology in MicroElectroMechanical System (MEMS) fabrication, particularly polysilicon surface micromachining. However, general LSI device CMP has partly distinction aspects, the pattern scale and material sorts in comparison with MEMS CMP. This study performed preliminary CMP tests to identify slurry characteristic used in general IC device. The experiment result is possible to verify slurry characteristic in MEMS structure material.

• 한국광학회지
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• 제7권2호
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• pp.150-156
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• 1996

본 연구에서는 RWG MQW-LD가 weakly index-guided LD로 동작하기 위한 최적 걸게조건으로부터, 수직형 LPE장치를 사용하여 RWG MQW-LD를 제작하였다. 먼저 수회의 실험을 통해 MQW-DH웨이퍼를 photolithofraphy공정을 통해 폭이 4.mu.m인 ridge 패턴을 형성시켜 RWG MQW-LD를 제작하였으며 전기광학적 특성을 조사한 결과 I=2.7I$_{th}$ 이상에서도 측방향 단일모드 동작함을 알 수 있었다.

• 소성∙가공
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• 제21권1호
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• pp.67-74
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• 2012

Although high productivity is possible, cold forged helical gears have not been widely used due to difficulty in achieving mechanical properties as well as dimensional accuracy of the product. Confidence in the gear characteristics also is very important in heavy-duty gear applications. Therefore, the properties of forged gears must be compared to the properties of conventional machined gears. The properties might be different due to the different fabrication processes. In this study, machined and forged products both before and after heat-treated have been compared by measuring the residual stress and involute curve of the tooth. Characteristics of hardness and microstructure were also compared. Additionally, tooth fracture strength was compared for the heat-treated products. Moreover, the tooth strength and the fracture pattern were compared between the machined and forged gears. The forged gear showed decreased changes in residual stress and decreased changes in dimensions when compared to the machined gear before and after heat treatment. The forged gear was over 10% better than the machined gear in tooth strength.