• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.194-201
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• 2005

Nanoscale fabrication of silicon substrate in an aqueous solution based on the use of atomic force microscopy was demonstrated. A specially designed cantilever with diamond tip, allowing the formation of damaged layer on silicon substrate easily by a simple scratching process (Tribo-Nanolithography, TNL), has been applied instead of conventional silicon cantilever for scanning. A slant nanostructure can be fabricated by a process in which a thin damaged layer rapidly forms in the substrate at the diamond tip-sample junction along scanning path of the tip and simultaneously the area uncovered with the damaged layer is being etched. This study demonstrates how the TNL parameters can affect the formation of damaged layer and the shape of 3-D structure, hence introducing a new process of AFM-based nanolithography in aqueous solution.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.4
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• pp.8-13
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• 2006

Nanoscale fabrication of silicon substrate in an aqueous solution based on the use of atomic force microscopy was demonstrated. A specially designed cantilever with a diamond tip, allowing the formation of a mask layer on the silicon substrate by a simple scratching process (Tribo-Nanolithography, TNL), has been applied instead of the conventional silicon cantilever for scanning. A slant nanostructure can be fabricated by a process in which a thin mask layer rapidly forms on the substrate at the diamond tip-sample junction along scanning path of the tip, and simultaneously, the area uncovered with the mask layer is etched. This study demonstrates how the TNL parameters can affect the formation of the mask layer and the shape of 3-D structure, hence introducing a new process of AFM-based nanolithography in aqueous solution.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.606-613
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• 2011

In this paper, patterns of laser scattering and detection of micro defects have been investigated based on Rayleigh criterion for silicon wafer in solar cell. Also, a new laser scattering mechanism is designed using characteristics of light scattering against silicon wafer surfaces. Its parameters are to be optimally selected to obtain effective and featured patterns of laser scattering. The optimal parametric ranges of laser scattering are determined using the mean intensity of laser scattering. Scattering patterns of micro defects are investigated at the extracted parameter region. Among a lot of pattern features, both maximum connected area and number of connected component in patterns of laser scattering are regarded as the important information for detecting micro defects. Their usefulness is verified in the experiment.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.56-64
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• 2005

A simple and cost-effective method for the electrostatic suspension of thin plates like silicon wafers is proposed which is based on a switched voltage control scheme. It operates according to a relay feedback control and deploys only a single high-voltage power supply that can deliver a DC voltage of positive and/or negative polarity. This method possesses the unique feature that no high-voltage amplifiers are needed which leads to a remarkable system simplification relative to conventional methods. It is shown that despite the inherent limit cycle property of the relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping origination from the air between the electrodes and levitated object. Using this scheme, a 4-inch silicon wafer was levitated stably with airgap variation decreasing down to $1 {\mu}m$ at an airgap of $100{\mu}m$.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.27-33
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• 2011

HCPV(High Concentrated PV) systems have well known for CPV market all over the world. Low concentration type silicon based modules have been introduced in the market. But low cost of standard flat silicon modules made them useless nowadays. High cost of compound semiconductor solar cell reduced cost effective cpv module production than that of recently silicon solar cell. In order to overcome increasing cost of CPV module, we study middle concentration type fresnel lens simulation using concentrated type silicon based solar cell. Linear type fresnel lens made production of CPV module without secondary optics such as light pipe or light tunnel. This type of fresnel lens design makes more cost effective solution for cpv niche market.

• Journal of Integrative Natural Science
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• v.3 no.1
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• pp.33-37
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• 2010

The functionalized photonic crystals of porous silicon biosensor was prepared for the application as a label-free biosensor based on distributed Bragg reflector interferometer. Prepared distributed Bragg reflector of porous silicon biosensor displayed sharp reflection in the optical reflective spectra. The mean of construction of molecular architectures on distributed Bragg reflector of porous silicon surfaces was investigated for the step-by-step binding interaction with amines, biotin, avidin, and biotinylated protein A. The subsequent introduction of avidin, and biotinylated protein A resulted in the reflectivity shifted to longer wavelengths, indicative of a change in refractive indices induced by binding of biomolecules.

• Journal of the Korean Magnetics Society
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• v.21 no.2
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• pp.67-76
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• 2011

Semiconductor spintronics is an emerging interdisciplinary technology based on the electron spin degree of freedom, combining the magnetic materials and semiconductors. The spin transistor represents a novel semiconductor device, in which the electron spin is injected, manipulated, and detected, and thereby a memory function and data processing function are enabled in one device. Particularly, the spin transistor based on Silicon, the mainstream semiconductor, might have a significant impact on information technology. This review introduces the major progresses of Silicon spintronics in recent years, and describes the technical issues for the future.

• Journal of the Semiconductor & Display Technology
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• v.9 no.4
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• pp.31-37
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• 2010

In this paper, optical deflection of laser scattering has been investigated based on Rayleigh criterion for crystalline silicon wafer in solar cell. A laser scattering mechanism is newly designed using light scattering properties in silicon wafer. Intensity distributions of laser scattering are different, depending on the incident angle of laser computed from Rayleigh criterion. In case of the incident angle satisfied with the criterion, they are asymmetric. Also, their specular reflection angle is shifted to unpredicted ones. These phenomena are in accordance with previous theories of laser scattering. The optical deflection of laser scattering is experimentally identified with the designed laser scattering mechanism. Its mathematical model is presented from the geometric relationship of laser scattering. It is shown that the optical deflection of laser scattering agree with the presented model, exclusive of grazing angles which is satisfied with Rayleigh criterion.

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.1-11
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• 2018

Several industrial applications such as space exploration, aerospace, automotive, the downhole oil and gas industry, and geothermal power plants require specific electronic systems under extremely high temperatures. For the majority of such applications, silicon-based technologies (bulk silicon, silicon-on-insulator) are limited by their maximum operating temperature. Silicon carbide (SiC) has been recognized as one of the prime candidates for providing the desired semiconductor in extremely high-temperature applications. In addition, it has become particularly interesting owing to a Si-compatible process technology for dedicated devices and integrated circuits. This paper briefly introduces a variety of SiC-based integrated circuits for use under extremely high temperatures and covers the technology trend of SiC CMOS devices and processes including the useful implementation of SiC ICs.

• Electronics and Telecommunications Trends
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• v.37 no.3
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• pp.11-22
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• 2022

The development and application of silicon photonics technology to terabit optical transmission are expected in the future. Silicon photonics technology is recognized as the only technology focusing on increasing the bandwidth of data center switches. High-density integration-based small optical subassemblies, optical engines, and optical transceivers are converged with the silicon photonics technology to accelerate a revolution in optical interfaces.