• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.452-455
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• 2003

[ $ZrO_2$ ] dielectric layers were grown on the p-type Si (100) substrate by metalorganic molecular beam epitaxy(MOMBE). Zrconium t-butoxide, $Zr(O{\cdot}t-C_4H_9)_4$ was used as a Zr precursor and Argon gas was used as a carrier gas. The thickness of the layers was measured by scanning electron microscopy (SEM) and the properties of the $ZrO_2$ layers were evaluated by X-ray diffraction, high frequency capacitance-voltage measurement. and HF C-V measurements have shown that $ZrO_2$ layer grown by MOMBE has a high dielectric constant (k=18-19). The growth rate is affected by various process variables such as substrate temperature, bubbler temperature, Ar, and $O_2$ gas flows.

• Korean Journal of Materials Research
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• v.15 no.2
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• pp.139-142
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• 2005

[ $ZrO_2$ ] gate dielectric thin films were deposited by radio frequency (rf)-magnetron sputtering and its structure, surface morphology and electrical peoperties were studied. As the oxygen flow rate increases, the surface becomes smoother. The experimental results indicate that a high temperature annealing is desirable since it improves the electrical properties of the $ZrO_2$ gate dielectric thin films by decreasing the number of interfacial traps at the $ZrO_2/Si$ interface. The carrier transport mechanism is dominated by the thermionic emission.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.220-221
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• 2007

Recently, imprint lithography have received significant attention due to an alternative technology for photolithography on high performance microelectronic devices. In this work, we investigated thermal stabilities and dynamic mechanical properties of dielectric materials for thermal imprint lithography. Curing behaviours, thermal stabilities, and dynamic mechanical properties of the dielectric materials cured with various curing agent and spherical filler were studied using dynamic differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), rheometer and universal test machine(UTM).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.760-763
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• 2003

Low Temperature Cofired Ceramics (LTCC) technology is a promising technology to integrate many devices in a module by embedding passive components. For the module substrate, most LTCC structures have dielectric constants below 10 to reduce signal delay time. Some components, which need high dielectric constants, have not been yet embedded in LTCC module. So, embedding capacitor with high capacitance by applying another dielectrics with high dielectric constants in LTCC is an important issue to maximize circuit density in LTCC module. In this study, electrical properties of embedded capacitor fabricated by dielectric paste of high dielectric constants (K-100) and co-firing behavior with LTCC were investigated. To prevent camber development of co-fired structure, constrained sintering process was tested. Dielectric properties of embedded capacitors were calculated from their capacitance and impedance value. Temperature coefficient of capacitance were also measured.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.12-12
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• 2008

Ruthenium is one of the noble metals having good thermal and chemical stability, low resistivity, and relatively high work function(4.71eV). Because of these good physical, chemical, and electrical properties, Ru thin films have been extensively studied for various applications in semiconductor devices such as gate electrode for FET, capacitor electrodes for dynamic random access memories(DRAMs) with high-k dielectrics such as $Ta_2O_5$ and (Ba,Sr)$TiO_3$, and capacitor electrode for ferroelectric random access memories(FRAMs) with Pb(Zr,Ti)$O_3$. Additionally, Ru thin films have been studied for copper(Cu) seed layers for Cu electrochemical plating(ECP) in metallization process because of its good adhesion to and immiscibility with Cu. We investigated Ru thin films by thermal ALD with various deposition parameters such as deposition temperature, oxygen flow rate, and source pulse time. Ru thin films were grown by ALD(Lucida D100, NCD Co.) using RuDi as precursor and $O_2$ gas as a reactant at 200~$350^{\circ}C$.

• Progress in Superconductivity and Cryogenics
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• v.14 no.1
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• pp.25-29
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• 2012

The novel type of cable under consideration is cooled by gaseous Helium at elevated pressure. Helium is known for having poor electric breakdown strength; therefore the dielectric capabilities of this type of cable must be tested under conditions similar to the envisaged operation. In order to study the dielectric performance we have designed and built a novel high pressure cryostat rated at 2.17 MPa which has been used for testing model cables of lengths of up to 1 m. The cryostat is an open system where the gas is not re-circulated. This allows maintaining a high purity of the gas. The target temperature range is between 40 K and 70 K. This substantially increases the critical current density of the HTS compared to 77 K, which is the typical temperature of cables cooled by liquid nitrogen. The cryostat presented allows for adjusting the temperature and keeping it constant for the time necessary to run a complete dielectric characterization test. We give a detailed description of the cryostat. Measurements of partial discharge inception voltages as well as the temperature distribution along the model cables as a function of time are presented.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.48.1-48.1
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• 2009

Performance of organic field-effect transistors (OFETs) with various temperature-cured polyacrylate(PA) copolymer as a gate insulator was studied. The PA thin film, which was cured at an optimized temperature, showed high dielectric strength (>7 MV/cm), low leakage current density ($5{\times}10^{-9}\;A/cm^2$ at 1 MV/cm) and enabled negligible hysteresis in MIS capacitor and OFET. A field-effect mobility of ${\sim}0.6\;cm^2/V\;s$, on/off current ratio (Ion/Ioff) of ${\sim}10^5$ and inverse subthreshold slope (SS) as low as 1.22 V/decwere achieved. The high dielectric strength made it possible to scale down the thickness of dielectric, and low-voltage operation of -5 V was successfully realized. The chemical changes were monitored by FT-IR. The morphology and microstructure of the pentacene layer grown on PA dielectrics were also investigated and correlated with OFET device performance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.348-348
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• 2008

In recent, the concept of system-on-package (SOP) for highly integrated multifunctional systems has been paid attention to for the miniaturization and high frequency of electronic devices. In order to realize SOP, co-integration of passive devices, such as capacitors, resistors and inductors, and active devices should be achieved. If ceramic thick films can be grown at room temperature, we expect to be able to overcome many problems in conventional fabrication processes. So, we focused on the aerosol deposition method (ADM) as room temperature fabrication technology. ADM is a novel ceramic coating method based on the Room Temperature Impact Consolidation (RTIC) phenomena. This method has a wide range potential for fabrication of co-integration of passive and active devices. In this paper, I will present the future potential of ADM introducing various ceramic dielectric thick films for the integration of electronic ceramics.

• Journal of the Korean Ceramic Society
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• v.43 no.11 s.294
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• pp.673-679
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• 2006

The discovery of ferroelectric barium titanate (BaTiO$_3$) in 1942 began the present era of dielectrics-based electronic ceramics. Ferroelectric barium titanate has a high dielectric constant and after the recognition of BaTiO$_3$ as a new ferroelectric compound, various attractive electrical properties have been extensively studied and reported. Since then, pioneering work on valence-compensated semiconduction led to the discovery of the positive temperature coefficient (PTC) of the resistance effect found in doped BaTiO$_3$. Significant progress has since followed with respect to understanding the PTC phenomena, advancing materials capabilities, and developing devices for sensor and switching applications. In this paper, the theoretical aspects of the various PTC models are discussed and the future trends of practical applications for PTC devices are briefly mentioned.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.05a
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• pp.125-129
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• 1992

When relaxation time will be distributed, TSC observed in the experimental procedure was analysed by using a potential model having two equilibrium positions and equations of dielectric properties was derived. Calculation of distribution was made by matrix method and compared/confirmed values obtained by TSC and alternating current which have a correspondence with each other. In this measurement, distribution of activation energy and relaxation time was determined by TSC peak at around 147k/364 of which center is 10$\^$-4/ sec/10$\^$5/ sec respectively at room temperature and also obtained dielctric loss factor at the range of 10$\^$-7/-10$\^$5/Hz. It seems that low temperature peak is local dispersion and high temperature peak have a relation to dielectric transition of the material.