• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.1-7
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• 2015

Road lighting is designed with a goal of achieving the related standards on luminance, uniformity ratio and glare. Unless the luminaire with LID which is perfect for road conditions is used, a situation which fails to meet lighting standards may occur. The study examined the relationship of maximum spacing with average road luminance and longitudinal uniformity. Based on the result of the analysis, this study evaluated luminaire with what characteristics are suitable to achieve lighting requirements of the roads and suggested methods of selection for luminaires depending on the size of the road.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.9
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• pp.438-443
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• 2001

In the shallow trench isolation(STI)-chemical mechanical polishing(CMP) process, the key issues are the optimized thickness control, within-wafer-non-uniformity, and the possible defects such as pad oxide damage and nitride residue. The defect like nitride residue and silicon (or pad oxide) damage after STI-CMP process were discussed to accomplish its optimum process condition. To understand its optimum process condition, overall STI related processes including reverse moat etch, trench etch, STI fill and STI-CMP were discussed. Consequently, we could conclude that law trench depth and high CMP thickness can cause nitride residue, and high trench depth and over-polishing can cause silicon damage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.9
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• pp.798-802
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• 2005

The plating shape in the opening of photoresist becomes gradated shape in the fountain plating system, because bubbles from the wafer surface are difficult to escape from the deep openings, vias. In this paper, the bubble flow from the wafer surface during plating process was studied and we designed the tilted electrode ring to get uniform bump height on all over the wafer and evaluated the film uniformity by SEM and $\alpha-step$. In a-step measurement, film uniformities in the fountain plating system and the tilted electrode ring contact system were $\pm16.6\%,\;\pm4\%$ respectively.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.451-457
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• 1995

Most important study on development of high-Tc superconducting magnet is magnetic properties with design conditions To study optimal design condition of high-Tc superconducting magnet, small size solenoid magnet was designed and simulated. Design conditions are radius of bobbin, radius of magnet, length of magnet, critical cur-rent and notch size. We know that intensity of magnetic fields was controled by critical current and uniformity of magnetic fields was controled by notch size. The optimal design conditions to get the high intensity and uniformity of magnetic field in this experiments were radius of bobbin=3[cm], radius of magnetic=12[cm], length of Z=10[cm], notch size=6[cm] and critical current=12[A].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.1-6
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• 2004

Dry etch characteristics of polysilicon with HBr/O$_2$ inductively coupled plasma (ICP) have been investigated. We determined etch late, uniformity, etch profiles, and selectivity with analyzing the cross-sectional scanning electron microscopy images obtained from top, center, bottom, right, and left positions. The etch rate of polysilicon was about 2500 $\AA$/min, which meets with the mass production for devices. The wafer level etch uniformity was within $\pm$5 ％. Etch profile showed 90$^{\circ}$ slopes without notches. The selectivity over photoresist was between 2:1∼4.5:1, depending on $O_2$ flow rate. The HBr-ICP etching showed higher PR selectivity, and sharper profile than the conventional Cl$_2$-RIE.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1756-1760
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• 2006

LTPS technology based on SLS Crystallization was intensively reviewed. LTPS structure produced by SLS crystallization is composed of much larger grains compared with conventional ELA crystallization structure, which can give higher TFT performances. However, TFT performance uniformity and anisotropy problem should be solved for it to be used in mass production. TFT performance uniformity was from main grain boundary position and could be solved by equal defect area structure $(EDAS^{TM})$. TFT performance anisotropy could be also solved by multi-channel (MC) structure that can make parallel component in perpendicular channel direction. The higher TFT performances from SLS technology can make superior optical and/or electrical properties and has been adopted in mass production successfully.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.11
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• pp.939-945
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• 2002

The rise throughput and the stability in the device fabrication can be obtained by applying chemical mechanical polishing (CMP) process in 0.18 $\mu\textrm{m}$ semiconductor device. However, it still has various problems due to the CMP equipment. Especially, among the CMP components, process variables are very important parameters in determining the removal rate and non-uniformity. In this paper, we studied the DOE (design of experiment) method in order to get the optimized CMP equipment variables. Various process parameters, such as table and head speed, slurry flow rate and down force, have investigated in the viewpoint of removal rate and non-uniformity. Through the above DOE results, we could set-up the optimal CMP process parameters.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.723-726
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• 2004

In this work, we have studied the CMP characteristics by mixing of original slurry and used slurry in order to investigated the possibility of recycle of used silica slurry. The removal rate and within-wafer non-uniformity (WIWNU) were measured as a function of different slurry composition. Also, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and the original slurry. Our experimental results revealed comparable removal rate and good planarity with commercial products.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.69-72
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• 2004

In order to use HTS tape on electric power applications, such as cable, motor, transformer, fault current limiter, a long length of HTS tape with a good uniformity of critical current is inevitable. The longer length of HTS tape, the wider in the range of application and the lower cost of HTS tape. In this study three long length Bi-2223/Ag tapes(268m, 253m and 187m) were fabricated. Critical current uniformity along the length was greatly improved through the optimization of cold deformation and thermo-mechanical process. Average critical current of the tapes was 63.2 A, 54.6 A and 64.2 A, respectively Critical tensile strength and critical bending radius (77 K, 5 % Ic degradation) was 135 MPa and 56 m, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.123-127
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• 2004

Cold cathode fluorescent lamp (CCFL) has been used as a light source for direct type backlights for LCD monitors or TV. One inverter for one CCFL was necessary for maintaining the lamp current so that many inverters were used to drive as many CCFLs of direct type backlight for LCD TV. An inverter for driving 16 CCFLs was developed to reduce the backlight cost. The length and diameter of CCFL were 450mm and 4mm, respectively. Backlight including 16 CCFLs for 26" LCD TV was assembled by using one inverter. The uniformities of the assembled backlight operated by the conventional inverter and the newly developed inverter were 75% and 88%, respectively.