• Korean Journal of Materials Research
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• v.13 no.2
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• pp.101-105
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• 2003

In this study, we have investigated the availability of the electroless Ni-B plating for a diffusion barrier of the bus electrode. The Ni-B layer of 1$\beta$: thick was electroless deposited on the electroplated Cu bus electrode for AC plasma display. The layer was to encapsulate Cu bus electrode to prevent from its oxidation and to serve as a diffusion barrier against Cu contamination of the transparent dielectric layer in AC plasma display. The microstructure of the as-plated barrier layer was made of an amorphous phase and the structure was converted to crystalline at about 30$0^{\circ}C$. The concentration of boron was about 5∼6 wt.% in the electroless Ni-B deposit regardless of DMAB concentration. The electroless Ni-B deposit was coated on the surface of the electroplated Cu bus electrode uniformly. And the electroless Ni-B plating was found to be an appropriate process to form the diffusion barrier.

• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.36-42
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• 2019

A macroporous Sn thick film as a high capacity negative electrode for a lithium ion secondary battery was prepared by using a chemical etching method using nitric acid for a Sn film having a thickness of $52{\mu}m$. The porous Sn thick film greatly reduced the over-voltage for the alloying reaction with lithium by the increased reaction area. At the same time. The porous structure of active Sn film plays a part in the buffer and reduces the damage by the volume change during cycles. Since the porous Sn thick film electrode does not require the use of the binder and the conductive carbon black, it has substantially larger energy density. As the concentration of nitric acid in etching solution increased, the degree of the etching increased. The etching of the Sn film effectively proceeded with nitric acid of 3 M concentration or more. The porous Sn film could not be recovered because the most of Sn was eluted within 60 seconds by the rapid etching rate in the 5 M nitric acid. In the case of etching with 4 M nitric acid for 60 seconds, the appropriate porous Sn film was formed with 48.9% of weight loss and 40.3% of thickness change during chemical acid etching process. As the degree of etching of Sn film increased, the electrochemical activity and the reversible capacity for the lithium storage of the Sn film electrode were increased. The highest reversible specific capacity of 650 mAh/g was achieved at the etching condition with 4 M nitric acid. The porous Sn film electrode showed better cycle performance than the conventional electrode using a Sn powder.

• Journal of the Korean Ceramic Society
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• v.42 no.12 s.283
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• pp.865-871
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• 2005

Submicron thick solid electrolyte membrane is essential to the implementation of low temperature solid oxide fuel cell, and, therefore, development of new electrode structures is necessary for the submicron thick solid electrolyte deposition while providing functions as current collector and fuel transport channel. In this research, a nickel membrane with multi-stage nano hole array has been produced via modified two step replication process. The obtained membrane has practical size of 12mm diameter and $50{\mu}m$ thickness. The multi-stage nature provides 20nm pores on one side and 200nm on the other side. The 20nm side provides catalyst layer and $30\~40\%$ planar porosity was measured. The successful deposition of submicron thick yttria stabilized zirconia membrane on the substrate shows the possibility of achieving a low temperature solid oxide fuel cell.

• Transactions on Electrical and Electronic Materials
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• v.4 no.2
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• pp.20-23
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• 2003

Piezoelectric powder with the composition of PbTiO$_3$-PbZrO$_3$-Pb(Mn$\_$1/3/Nb$\_$2/3/)O$_3$ and small particle size of 0.3 $\mu\textrm{m}$ was investigated for low-temperature firing of PZT thick films. PbTiO$_3$-PbZrO$_3$-Pb(Mn$\_$1/3/Nb$\_$2/3)O$_3$ ceramics showed dense microstructure and superior piezoelectric properties, electromechanical coupling factor (k$\_$p/) of 0.501 and piezoelectric constant (d$\_$33/) of 224. The PZT paste was made of the powder and organic vehicles, and screen-printed on Pt(450nm)/YSZ(110nm)/SiO$_2$(300nm)/Si substrates and fired at 800∼900$^{\circ}C$. Any interface reaction between the PZT thick film and the bottom electrode was not observed in the PZT thick films. The PZT thick film fired at 800$^{\circ}C$ showed moderate electrical properties, the remanent polarization(p$\_$r/) of 16.0 ${\mu}$C/$\textrm{cm}^2$, the coercive field(E$\_$c/) of 36.7 ㎸/cm, and dielectric constant ($\varepsilon$$\_$r/) of 531. Low-temperature sinterable piezoelectric composition and high activity of fine particles reduced the sintering temperature of the thick film. This PZT thick film could be utilized for piezoelectric microactuators or microsensors that require Si micromachining technology.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.965-968
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• 2004

Effective transverse Piezoelectric Coefficients $(e_{31,f})$ of thick PZT $(Pb(Zr_{0.52}Ti{0.48}Ti_{0.48})O_3)$ films on $SiN_x/Si$ substrates were measured with PZT thicknesses and top electrode dimensions. $e_{31,f}$ is one of important Parameters characterizing Piezoelectricity of PZT films. Thick PZT films have been used as various sensors and actuators because of their high driving force and high breakdown voltage. Thick PZT films were fabricated on Pt/Ta/$SiN_x$/Si substrates using sol-gel method. Thicknesses of PZT films were $1{\mu}m$ and $1.8{\mu}m$. $|e_{31,f}|$ values of $1.8{\mu}m$-thick-PZT films were higher than those of $1{\mu}$-thick-PZT films. Maximum $|e_{31,f}|$ of $1.8{\mu}$-thick-PZT films was about $50^{\circ}C/m^2$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1782-1792
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• 1994

Ti : $LiNbO_3$ traveling-wave phase optical modulators at wavelength 1.3㎛ have been designed and fabricated, focusing on the optical waveguide and asymmetric coplanar electrode structure. To improve the phase-mismatch of traveling-wave ACPS electrode, the characteristic impedance, effective microwave index, and electrode loss have been presented as a function of geometric parameters including electrode and buffer layer thickness. Low-loss channel optical waveguides on $LiNbO_3$ were fabricated by the Ti diffusion method with $O_2$ water-vapor environment. $2.5{\mu}m$ thick electrode was successfully fabricated by double-spin image reversal process. Modulation bandwidth was limited by a resonance at 2.9 GHz and modulation bandwidth up to 2.5GHz was approxirnately measured.

• Journal of information and communication convergence engineering
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• v.1 no.3
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• pp.129-132
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• 2003

In this paper, cobalt (Co)-electrode FBAR devices fabricated on seven-layered Bragg Reflectors are presented along with their resonance characteristics. ZnO films are used as the resonating material in FBAR devices where the Co electrode is 3000${\AA}$ thick. All processes are preformed in an RF magnetron sputtering system. As a result of characterization, the resonance characteristics are observed to depend strongly on the quality of ZnO film and Bragg Reflectors. In addition, the FBAR devices with W/$SiO_2$ reflectors show good resonance characteristics in term of return loss and quality-factor (Q-factor).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.926-929
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• 2003

The dissolved oxygen sensor of thick film type was fabricated by screen print method and measured the characteristic, reference electrode used Ag/AgCl, and working electrode used Pt. The devices are continuously powered at potential of $0.7V{\sim}0.8V$ versus Ag/AgCl reference electrode and results indicated that the response characteristic of sensor was $1.002{\mu}A{\sim}19.792{\mu}A$ for thirty seconds. we can know that it is good linearity when compared with of existent dissolved oxygen meter. Therefore sensor fabricated excels sensitivity for dissolved oxygen and will be considered to be applied typically because the price is costly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.9
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• pp.728-732
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• 2008

This paper presents ion-based micro vibration sensor for the ultra-high frequency vibration detection. Presented sensor uses the motion of anion and cation in an electrolyte. Electrolyte vibration sensors have the high shock survival characteristics and a simple read-out circuit because of the small mass and own charges of ions. Presented sensor measures the induced electric potential by the mechanical-electrical coupling. It consist of electrolyte chamber and detection electrode. Electrolyte chamber was fabricated by PDMS molding. Detection electrode was made of gold evaporation on pyrex glass. Size of electrolyte chamber was designed as $600{\times}600{\times}100um$. Detection electrode had 200nm-thick and 42um-gap. In the experimental study, 5.8M sodium Chloride (NaCl) solution was used as electrolyte in 36nl-chamber. Mechanical vibration was measured from 2kHz to 4MHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.381-384
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• 2003

In this paper, cobalt (Co)-electrode FBAR devices fabricated on seven-layered Bragg Reflectors are presented along with their resonance characteristics. ZnO films are used as the resonating material in FBAR devices where the Co electrode is 3000$\AA$ thick. All processes are preformed in an RF magnetron sputtering system. As a result of characterization, the resonance characteristics are observed to depend strongly on the quality of ZnO film and Bragg Reflectors. In addition, the FBAR devices with W/SiO$_2$ reflectors show good resonance characteristics in term of return loss and quality-factor (Q-factor).