• Journal of the Korean Vacuum Society
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• v.11 no.4
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• pp.230-234
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• 2002

Metal-ferroelectric-semiconductor(MFS) capacitors by using rapid thermal annealed $LiNbO_3$/Si structures were successfully fabricated and demonstrated nonvolatile memory operations of the MFS capacitors. The C-V characteristics of MFS capacitors showed a hysteresis loop due to the ferroelectric nature of the $LiNbO_3$thin film. The dielectric constant of the $LiNbO_3$film calculated from the capacitance in the accumulation region in the capacitance-voltage(C-V) curve was about 25. The gate leakage current density of MFS capacitor using a platinum electrode showed the least value of $1{\times}10^{-8}\textrm{A/cm}^2$ order at the electric field of 500 kV/cm. The minimum interface trap density around midgap was estimated to be about $10^{11}/cm^2$.eV. The typical measured remnant polarization(2Pr) value was about 1.2 $\mu\textrm{C/cm}^2$, in an applied electric field of $\pm$ 300 kv/cm. The ferroelectric capacitors showed no polarization degradation up to about $10^{10}$ switching cycles when subjected to symmetric bipolar voltage pulse in the 500 kHz.

• Journal of the Korean Vacuum Society
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• v.9 no.2
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• pp.162-166
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• 2000

High quality $Si_3N_4$ metal-insulator-metal (MIM) capacitors were realized by plasma enhanced chemical vapor deposition (PECVD). Titanium nitride (TiN) adapted as a diffusion barrier reduced the interfacial reaction between $Si_3N_4$ dielectric layer and aluminum metal electrode showing neither hillock nor observable precipitate along the interface. The capacitance and the current-voltage characteristics of the MIM capacitors showed that the minimum thickness of $Si_3N_4$ layer should be limited to 500 $\AA$ under the present process, below which most of the capacitors were electrically shorted resulting in the devastation of on-wafer yield. According to the transmission electron microscopy (TEM) on the cross-sectional microstructure of the capacitors, the dielectric breakdown was caused by slit-like voids formed at the interface between TiN and $Si_3N_4$ layers when the thickness of $Si_3N_4$ layer was less than 500 $\AA$. Based on the calculation of thermally-induced residual stress, the formation of voids was understood from the mechanistic point of view.

• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.36-42
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• 2007

In general, the battery and the(electric) condenser are pictured as electrical energy storage devices. Although there were lots of inventions and utilizations of morden conveniences according to enormous growth of the science and technologies after the Industrial Revolution, a speed of technology development on these devices being closely used in civilized human lives and many electric or electronic systems as a core component are relatively slower to the other fields of technologies. Nevertheless, based on a remarkable progress of the material science and technologies for the last ten years, a new type of electrical energy storage device so called as 'electrochemical capacitors' are being developed and used practically. The electrochemical capacitors exhibit their own characteristics of much enhanced capacitance over the conventional condensers and also distinctively exhibit a longer lift time and higher power capability that the nickel hydrogen batteries and secondary batteries such as lithium ion and polymer batteries does not show up so for. Hence, in this paper, it is intended to introduce a fundamental understanding and updated technology trends on the electrochemical capacitors.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1661-1663
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• 2001

This paper describes the dielectric characteristics of composite dielectric film for pulsed power capacitors. The relative electric permittivity(${\varepsilon}'$) and the dielectric dissipation factor(tan$\delta$) were measured for polypropylene (PP) membranes, kraft paper for capacitors(CP) and composite dielectric films(PP+CP), respectively, in a frequency range of $1{\sim}10^4$[Hz], and in temperatures ranging from -50[$^{\circ}C$] to 110[$^{\circ}C$]. As a result, the variation of the electric permittivity was observed similarly for PP and CP. Dielectric dispersion was observed in frequency domain in PP, CP and composite dielectric films.

• Journal of Electrical Engineering and Technology
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• v.1 no.2
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• pp.251-256
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• 2006

To design the effective usage of electric double layer capacitors (EDLCs) used for a storage device of dye sensitized solar cell (DSC) energy, we first investigated the accumulation state of electrical charges and the charge behavior in the EDLCs. Based on the results, the voltage characteristics of EDLCs connected to DSC energy were evaluated. The results showed that the charge accumulation region concentrated on the central part of the carbonaceous electrode in EDLCs and the required times for charging and discharging were almost the same.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1391-1393
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• 2002

There arc some problems on storage batteries which are called Secondary Battery, such as long charging time, limited cycle life, low coulomb efficiency and inaccurate residual power meter. To solve those problems, a complex system of capacitors and Super Capacitors of increased energy density. Though the capacitors alone arc not capable of delivering stable output, the accompanied circuits compensate the various characteristics all through the charge-and discharge-cycle. This paper deals with Energy Storage System with Super Capacitor for PV System Discussed in this paper are, explains the accompanied circuits of Super Capacitor which is compared with the Second Batteries.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.73-73
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• 2009

In this paper, electrical properties in $ZrO_2$-based high-k metal MIM capacitors were studied. Linear voltage coefficient of capacitance (VCC) was 72.375 ppm/V, quadratic VCC was $174.581ppm/V^2$, temperature coefficients of capacitance was $111.01ppm/^{\circ}C$ at 100kHz and $89.497ppm/^{\circ}C$ at 1MHz, which indicate the temperature dependence of electrical parameter for MIM capacitors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.77-81
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• 2003

The $Sr_{0.7}Bi_{2.6}Ta_2O_9$(SBT) thin films are deposited on Pt-coated electrode(Pt/$TiO_2/SiO_2$/Si) using RF magnetron sputtering method. The structural and electrical properties of SBT capacitors were influenced with annealing atmosphere. In the XRD pattern, the SBT thin films in all annealed atmosphere had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized in all annealing atmosphere and grains largely grew in oxygen annealing atmosphere. The dielectric constant and leakage current density of capacitors annealed oxygen atmosphere are 340 and $2.13{\times}10^{-9}[A/cm^2]$ respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.213-220
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• 2006

This paper investigates how the PCB power-bus sturcture's characteristics are influenced by the loading of decoupling capacitors in conjunction to other lumped elements including vias. The fields and impedance profiles are rigously evaluated and analyzed on various cases loaded with the above components and their effects will be given to bring better PCB EMC countermeasurs.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.429-432
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• 2005

This paper investigates how the PCB power-bus structure's characteristics are influenced by the loading of decoupling capacitors that are placed close to vias, on purpose or not. It is worthwhile to see the correlated effects of the aforementioned lumped elements in that when they inevitably share one DC power-bus they will result in positive or negative changes in the PCB EMC design. The EM fields and impedance profiles are rigously calculated on the PCB power-bus cases loaded with the above components and their effects will be given to bring better PCB EMC countermeasures.