• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.260-263
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• 2004

During the last few years, there have been many efforts on the fabrication of electronic and optical devices based on semiconductor nanowires. Room-temperature ultraviolet lasing in GaN nanowire, ultraviolet light sensing in ZnO nanowire, and dramatically improved hall mobility in Si nanowire have been demonstrated in this article. The studies on semiconductor nanowire based electronic and optical device is reviewed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1007-1009
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• 2004

We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface with polymer film using rubbing and photoalignment method. Monodomain alignment of the plastic STN-LCD can be observed. A faster response time for the photoaligned plastic STN-LCD on the polyimide(PI) surfaces can be achieved than rubbingaligned plastic STN-LCD.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.202-205
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• 2004

We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface using polymer film. The NLC pretilt angles generated are about $18^{\circ}$ by the rubbing alignment method on thin plastic substrates. However, the pretilt angle are at about $13^{\circ}$ lower on the glass substrate than on thin plastic substrate. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance(V-T) curve of the plastic STN-LCD was observed on the polyimide(PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide(PI) surfaces using polymer film can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.113-116
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• 1993

A guided - wave electro - optical modulatored directional coupler $2{\times}2$ was fabricated on X-cut $LiNbO_3$ by proton exchange wi th self-aligned method. The Electode pattern was formed by the four extra gap electrode separtion within self-aligned electrode mask. Initial cross over state turned that by controlling the anneal ing process and self-aligned electrodes are used in fabricating the electro-optical modulatored directional coupler $2{\times}2$. The modulatored directional coupler $2{\times}2$ has very good figures of merits: the measured crosstalk was -28.2 dB and the modulating valtage of 3.2[V].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.27-27
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• 2010

This paper describes the electrical and optical characteristics of $N_2$ doped porous 3C-SiC films. Average pore diameter is about 30 nm and etched area was increased with $N_2$ doping rate. The mobility was dramatically decreased in porous 3C-SiC. The band gaps of polycrystalline 3C-SiC films and doped porous 3C-SiC were 2.5 eV and 2.7 eV, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.229-230
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• 2008

We have studied the structural and optical properties of ZnO thin film deposited on glass by RF magnetron sputtering as functions of working pressures. The grain sizes were decreased as the working pressures were increased. The average optical transmissions over all exceeded 80% for ZnO films deposited in 20, 25 and 300m torr working pressures. And the transmission spectra patterns were almost same. While the transmission spectra pattern of ZnO film deposited in 35nm torr was different with other spectra patterns obtained in 20, 25 and 30nm torr working pressures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1072-1075
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• 1997

To enhance the effective data transfer rate the multi-beam optical disk drive is presented. The Beam rotating actuator is necessary for putting multi-beam on more than one track. Ray tracing was also executed for real system set-up. The Beam Rotating Actuator is made up of piezoelectric material, high stiffness wire hinge and dove prism. The actuator has about 1kHz natural frequency and suitable and suitable operational range. The dynamic equation for the actuator is derived for the control of real system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.3026-3032
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• 2000

To enhance the effective data transfer rate the multi-beam optical disk drive is presented. The Beam rotating actuator is necessary for putting multi-beam on more than one track. Ray tracing was also executed for real system set-up. The beam Rotating Actuator is made up of piezoelectric material, high stiffness wire hinge and dove prism. The actuator has about 1kHz natural frequency and suitable operational range. The dynamic equation for the actuator is derived for the control real system.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.154-159
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• 2000

A multi-beam optical disk drive is presented as a method for improving the effective data transfer rate by increasing the beam spot number formed on an optical disk. The beam rotating actuator is necessary for putting multi-beam on more than one track. The beam rotating actuator is made up of piezoelectric material, high stiffness wire hinge and dove prism. The actuator has good frequency response above 1KHz and suitable operational range. The dynamic equation for the actuator is derived.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.332-336
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• 2001

In this study, the reaction at UBM(Under Bump Metallurgy) and solder interface was investigated. The UBM employed in conventional optical packages, Au/Pt/Ti layer, were found to dissolve into molten Au-Sn eutectic solder during reflow soldering. Therefore, the reaction with different diffusion barrier layer such as Fe, Co, Ni were investigated to replace the conventional Pt layer. The reaction behavior was investigated by reflowing the solder on the pad of the metals defined by Cr layer for 1, 2, 3, 4, and 5 minutes at $330^{\circ}C$. Among the metals, Co was found to be most suitable for the diffusion barrier layer as the wettability with the solder was reasonable and the reaction rate of intermetallic formation at the interface is relatively slow.