• Electrical & Electronic Materials
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• v.10 no.5
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• pp.492-499
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• 1997

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1115-1118
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• 2006

Using a thermally-crosslinkable organosiloxane-based organic-inorganic hybrid material, solution processable gate dielectric layer for organic thin-film transistors (OTFTs) have been fabricated. The hybrid dielectrics are synthesized by the sol-gel process, followed by the heat-treatment at $190{\bullet}\;.{\bullet}$ To investigate the electrical property of hybrid dielectric, leakage current behavior and capacitance were measured. To fabricate coplanar-type OTFTs, Au/Cr electrode was deposited onto the heavily doped silicon substrate with the organic-inorganic hybrid dielectric layer and then ${\alpha},{\omega}-dihexylquaterthiophene$ was drop-cast between source and drain electrical performance of the fabricated transistor.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2005.09a
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• pp.201-212
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• 2005

[ $Epoxy/BaTiO_3$ ] composite embedded capacitor films (ECFs) were newly designed fur high dielectric constant and low tolerance (less than ${\pm}15\%$) embedded capacitor fabrication for organic substrates. In terms of material formulation, ECFs are composed of specially formulated epoxy resin and latent curing agent, and in terms of coating process, a comma roll coating method is used for uniform film thickness in large area. Dielectric constant of $BaTiO_3\;&\;SrTiO_3$ composite ECF is measured with MIM capacitor at 100 kHz using LCR meter. Dielectric constant of $BaTiO_3$ ECF is bigger than that of $SrTiO_3$ ECF, and it is due to difference of permittivity of $BaTiO_3\;and\;SrTiO_3$ particles. Dielectric constant of $BaTiO_3\;&\;SrTiO_3$ ECF in high frequency range $(0.5\~10GHz)$ is measured using cavity resonance method. In order to estimate dielectric constant, the reflection coefficient is measured with a network analyzer. Dielectric constant is calculated by observing the frequencies of the resonant cavity modes. About both powders, calculated dielectric constants in this frequency range are about 3/4 of the dielectric constants at 1 MHz. This difference is due to the decrease of the dielectric constant of epoxy matrix. For $BaTiO_3$ ECF, there is the dielectric relaxation at $5\~9GHz$. It is due to changing of polarization mode of $BaTiO_3$ powder. In the case of $SrTiO_3$ ECF, there is no relaxation up to 10GHz. Alternative material for embedded capacitor fabrication is $epoxy/BaTiO_3$ composite embedded capacitor paste (ECP). It uses similar materials formulation like ECF and a screen printing method for film coating. The screen printing method has the advantage of forming capacitor partially in desired part. But the screen printing makes surface irregularity during mask peel-off, Surface flatness is significantly improved by adding some additives and by applying pressure during curing. As a result, dielectric layer with improved thickness uniformity is successfully demonstrated. Using $epoxy/BaTiO_3$ composite ECP, dielectric constant of 63 and specific capacitance of 5.1nF/cm2 were achieved.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.2
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• pp.35-40
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• 2010

The variations of dielectric properties of $Ta_2O_5-SiO_2$ continuous composition spread thin films prepared by off-axis radio-frequency magnetron sputtering were investigated. The dielectric maps of dielectric constant and loss were plotted via 1500 micron-step measuring. The specific points showing superior dielectric properties of high dielectric constant (k~19.5) and loss (tan${\delta}$<0.05) at 1 MHz were found in area of the distance of 16 mm and 22 mm apart from $SiO_2$ side in $75{\times}25mm^2$ sized Pt/Ti/$SiO_2$/Si(100) substrates.

• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.178-183
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• 2016

Ferroelectric relaxor ceramics with $BaTiO_3-NaNbO_3-Bi(Mg_{1/2}Ti_{1/2})O_3$ ternary compositions (BT-NN-BMT) have been prepared by sol-gel powder synthesis and consequent bulk ceramic processing. Through the modified chemical approach, fine and single-phase complex perovskite compositions were successfully obtained. Temperature and frequency dependent dielectric properties indicated typical relaxor characteristics of the BT-NN-BMT compositions. The ferroelectric-paraelectric phase transition became diffusive when NN and BMT were added to form BT based solid solutions. BMT additions to the BT-NN solid solutions affected the high temperature dielectric properties, which might be attributable to the compositional inhomogeneity of the complex perovskite and resulting weak dielectric coupling of the Bi-containing polar nanoregions (PNRs). The temperature stability of the dielectric properties was good enough to satisfy the X9R specification. The quasi-linear P-E response and the temperature- stable dielectric properties imply the high potential of this ceramic compound for use in high temperature capacitors.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.610-615
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• 2022

BaTiO₃ is one of the ferroelectric materials with excellent dielectric properties such as high dielectric constant, low dielectric loss, and is widely used for the manufacturing of capacitors, piezoelectric converters, microsensors, and ferroelectric memories. Inkjet printing is a technology which uses digital and contactless methods which significantly improves flexibility associated with material and structural design, reducing manufacturing costs. Therefore, the top and bottom electrodes, BaTiO₃ ink, and photocurable resin were all printed by an inkjet to produce a BaTiO₃ capacitor. The properties of the printed thin film were analyzed. It was confirmed that the photocurable resin ink was well-infiltrated between the BaTiO₃ powder particles printed by inkjet. The dielectric properties of the capacitor such as dielectric constant which varies in accordance with frequency, polarization and tunability that changes with voltage, were measured.

• Korean Journal of Materials Research
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• v.22 no.7
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• pp.342-345
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• 2012

The dielectric properties and phase transformation of poled <001>-oriented $Pb(Mg_{1/3}Nb_{2/3})O_3-x%PbTiO_3$(PMN-x%PT) single crystals with compositions of x = 20, 30, and 35 mole% are investigated for orientations both parallel and perpendicular to the [001] poling direction. An electric-field-induced monoclinic phase was observed for the initial poled PMN-30PT and PMN-35PT samples by means of high-resolution synchrotron x-ray diffraction. The monoclinic phase appears from $-25^{\circ}C$ to $100^{\circ}C$ and from $-25^{\circ}C$ to $80^{\circ}C$ for the PMN-30PT and PMN-35PT samples, respectively. The dielectric constant (${\varepsilon}$)-temperature (T) characteristics above the Curie temperature were found to be described by the equation$(1/{\varepsilon}-1/{\varepsilon}_m)^{1/n}=(T-T_m)/C$, where ${\varepsilon}_m$ is the maximum dielectric constant and $T_m$ is the temperature giving ${\varepsilon}_m$, and n and C are constants that change with the composition. The value of n was found to be 1.82 and 1.38 for 20PT and 35PT, respectively. The results of mesh scans and the temperature-dependence of the dielectric constant demonstrate that the initial monoclinic phase changes to a single domain tetragonal phase and a to paraelectric cubic phase. In the ferroelectric tetragonal phase with a single domain state, the dielectric constant measured perpendicular to the poling direction was dramatically higher than that measured in the parallel direction. A large dielectric constant implies easier polarization rotation away from the polar axis. This enhancement is believed to be related to dielectric softening close to the morphotropic phase boundary.

• Electrical & Electronic Materials
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• v.7 no.6
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• pp.527-533
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• 1994

In this study, it was studied on dielectric breakdown strength and thennostability properties due to the structure variation of matrix resin and treatment of coupling agent of epoxy insulating materials. The interpenetrating network structure was formed by simultaneous heating curing the epoxy resin with single network structure and the methacrylic acid resin. Also inner structure was observed and the glass transition temperature was measured on these three type specimens. Dielectric breakdown properties were investigated by applying DC, AC and impulse voltage. As a result, the glass transition temperature and the dielectric breakdown strength of specimen with interpenetrating network structure was more higher than another two type specimens.

• Korean Journal of Materials Research
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• v.11 no.11
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• pp.923-928
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• 2001

An electrolytic silver plating process has been successfully developed for terminated electrode parts of dielectric ceramic resonator. High adhesion strength and high Qu is obtained and blister occurance is minimized under plating condition with $HNO_3$750 $m\ell/\ell$ and HF $ 250m\ell/\ell$ solution at $25^{\circ}C$ for 20 minutes. Adhesion strength has the highest value, 3.2 kg/mm$^2$ at etching temperature of $25^{\circ}C$. Adhesion strength, Qu and blister occurance are monotonically increased with the thickness of electrodeposition layer. In case of electrodeposition of Ag, Qu value of 380 has obtained higher than in case of electrolytic Cu plating with Qu value of 325. Therefore, terminated electrode parts of dielectric ceramic resonator reducing dielectric loss can be obtained using prensent process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.53-56
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• 2008

The commercial parallel plate electrodes system with guard-ring electrode have been widely used for measurement of dielectric constants of solid materials. And the specification of the electrodes system is about 1 % of measurement uncertainty. This measurement uncertainty is only estimated the error come from mechanical measurements such as the area of the electrodes and the gap between the electrodes except the error come from the air gap between the electrodes and dielectric specimen. Because it is impossible to measure the air gap. This study analyze the total measurement uncertainties of the commercial dielectric constant test cell using 3 kinds of Standard Reference Materials. As a results, the total measurement uncertainty is much bigger than 1 % and the most of the uncertainty can be reduced by compensation of the error values evaluated in this study.