• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.696-699
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• 2003

본 연구에서는 MDFM (Metal-Dielectric-ferroelectric-Metal) 구조의 강유전체 캐패시터와 수정된 Sawyer-Tower 회로를 접목시켜 강유전체의 이력곡선을 정밀하게 계산하기 위한 모델을 제시하였다. 본 모델은 스위칭 쌍극자 분극의 수학적 표현을 수치적분 알고리즘에 적용하였으며, 강유전체와 하부전극사이에 dielectric 층을 포함시켜 피로특성을 고려할 수 있다. 본 모델의 예측치를 PLT(10) 강유전체 박막의 측정결과와 비교하여 본 모델의 유효성을 입증하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.197-197
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• 2008

There are fast growing demands for new dielectric materials for passive capacitors of RF-ICs and other wireless applications. One of the bulk microwave dielectric materials which have superior properties is $ZrTiO_4$ due to its large dielectric constant and high quality factor. Therefore, $ZrTiO_4$ is worth studying as a form of thin film to be applied for passive capacitors of integrated circuits. In this study, we fabricated metal-insulator-metal type capacitors with $ZrTiO_4$ dielectric thin film, and evaluated their capacitor properties.

• 한국전기전자재료학회논문지
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• 제22권1호
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• pp.53-60
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• 2009

$ZrTiO_4$ dielectric thin films were coated by metal-organic decomposition, and annealed by rapid thermal processing up to $900^{\circ}C$ for their crytallization. Crystallized single-phase $ZrTiO_4$ thin films were fabricated above the annealing temperature of $800^{\circ}C$, but their grains were randomly oriented without specific textured orientation. Best dielectric properties were presented by the sample annealed at $800^{\circ}C$ which had crystalline structure and flat surface. Dielectric constant of the film was maintained at 32 throughout full frequency range up to 6 GHz, and dielectric loss was varied between 0.01 and 0.04.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권1호
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• pp.1-9
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• 2002

Effects of temperature coefficients fur dielectric constants on transient reflectances and thermal responses have been investigated for a metal(gold) thin-film during ultrashort pulse laser heating. Heating processes are simulated using the conventional conduction model(parabolic one-step, POS), the parabolic tow-step model(PTS), the hyperbolic two-step model(HTS). Results fro the HTS model are very similar to those from the PTS model, since the laser heating time in this study is considerably greater than the electron relaxation time. PTS and HTS models, however, result in completely different temperature profiles from those obtained by the POS model due to slow electron-lattice interactions compared to laser pulse duration. Transient reflectances are directly estimated from the linear relationship between electron temperature and complex dielectric constants, while conventional approaches assume that the change in reflectances is proportional to that in temperatuer. Reflectances at the front surface vary considerably for various dielectric constants, while those at the rear surface remain unchanged relatively.

• 한국전기전자재료학회논문지
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• 제23권4호
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• pp.311-316
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• 2010

$Zr_{0.7}Sn_{0.3}TiO_4$ (ZST) thin films were fabricated by metal-organic decomposition, and their dielectric properties were investigated in order to evaluate their potential use in passive capacitors for rf and analog/mixed signal integrated circuits. The ZST thin film annealed at the temperature of $800^{\circ}C$ showed a dielectric constant of 27.3 and a dielectric loss of 0.011. The capacitor using the ZST film had quadratic and linear voltage coefficient of capacitance (VCC) of -65 ppm/$V^2$ and -35 ppm/V at 100 kHz, respectively. It also exhibited a good temperature coefficient of capacitance (TCC) value of -32 ppm/$^{\circ}C$ at 100 kHz.

• 설비공학논문집
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• 제11권4호
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• pp.528-536
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• 1999

This work studies the effects of transient reflectance on the thermal responses of a metal(gold) thin-film during ultrashort laser heating. The heating process is calculated using the conventional conduction model (parabolic one-step: POS), parabolic two-step model (PTS) with and without variable properties, hyperbolic two-step model (HTS). Results from the HTS model are very similar to those from the PTS model, since the laser heating time in this study is greater than the electron relaxation time. PTS model with variable properties, however, results in totally different temperature profiles compared to those from POS models or calculation with constant properties. Transient reflectances are estimated from electron temperature distributions and based on the linear relationship between the electron temperature and complex dielectric constants. Reflectance of the front surface can be changed with respect to dielectric constants, while those of the rear surface remain unchanged.

• Transactions on Electrical and Electronic Materials
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• 제12권3호
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• pp.110-114
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• 2011

Polymeric films of high chemical stability and mechanical strength covered with a thin metallic film have been extensively used in various fields as electric and electronic materials. In this study, we have chosen polypropylene (PP) as the polymer due to its outstanding chemical resistance and good creep resistance. We coated thin nickel film on PP films by the electroless plating process. The surfaces of PP films were pre-treated and modified to increase the adhesion strength of metal layer on PP films, prior to the plating process, by an environment-friendly process with atmospheric plasma generated using dielectric barrier discharges in air. The surface morphologies of the PP films were observed before and after the surface modification process using a scanning electron microscope (SEM). The static contact angles were measured with deionized water droplets. The cross-sectional images of the PP films coated with thin metal film were taken with SEM to see the combined state between metallic and PP films. The adhesion strength of the metallic thin films on the PP films was confirmed by the thermal shock test and the cross-cutting and peel test. In conclusion, we made a composite material of metallic and polymeric films of high adhesion strength.

• Macromolecular Research
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• 제15권3호
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• pp.211-215
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• 2007

Hybrid thin film nanostructures composed of metal nanoparticles (NPs) and self-assembled polymer films with different spatial distributions of NPs were analyzed by optical waveguide spectroscopy (OWS). Specifically, the dielectric constants were calculated using effective medium theory for the incorporation of 1 vol% Au NP into the block copolymer (BCP) films having a cylindrical nanodomain morphology. Three cases were considered: uniform distribution of NPs in the film; selective distribution of NPs only in the cylindrical domains; and segregation of NPs to the center of the cylindrical domains. The optical waveguide spectra derived from the calculated dielectric constants demonstrate the feasibility of experimentally distinguishing the composite nanostructures with different inner morphologies in the hybrid metal NP-BCP nanostructures, by the measurement of the dielectric constants using OWS.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.319-319
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• 2013

Even though the fabrication methods of metal oxide based thin film capacitor have been well established such as RF sputtering, Sol-gel, metal organic chemical vapor deposition (MOCVD), ion beam assisted deposition (IBAD) and pulsed laser deposition (PLD), an applicable capacitor of printed circuit board (PCB) has not realized yet by these methods. Barium Strontium Titanate (BST) and other high-k ceramic oxides are important materials used in integrated passive devices, multi-chip modules (MCM), high-density interconnect, and chip-scale packaging. Thin film multi-layer technology is strongly demanded for having high capacitance (120 nF/$mm^2$). In this study, we suggest novel multi-layer thin film capacitor design and fabrication technology utilized by plasma assisted deposition and photolithography processes. Ba0.6Sr0.4TiO3 (BST) was used for the dielectric material since it has high dielectric constant and low dielectric loss. 5-layered BST and Pt thin films with multi-layer sandwich structures were formed on Pt/Ti/$SiO_2$/Si substrate by RF-magnetron sputtering and DC-sputtering. Pt electrodes and BST layers were patterned to reveal internal electrodes by photolithography. SiO2 passivation layer was deposited by plasma-enhanced chemical vapor deposition (PE-CVD). The passivation layer plays an important role to prevent short connection between the electrodes. It was patterned to create holes for the connection between internal electrodes and external electrodes by reactive-ion etching (RIE). External contact pads were formed by Pt electrodes. The microstructure and dielectric characteristics of the capacitors were investigated by scanning electron microscopy (SEM) and impedance analyzer, respectively. In conclusion, the 0402 sized thin film multi-layer capacitors have been demonstrated, which have capacitance of 10 nF. They are expected to be used for decoupling purpose and have been fabricated with high yield.

• 한국전기전자재료학회논문지
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• 제25권5호
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• pp.366-371
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• 2012

In this paper, fabricated by MEMS uncooled micro-bolometer detector for the study in the infrared sensitivity enhancement. Absorption layer SiOx-Metal series MDTF (metal-dielectric thin film) by high absorption rate and has a high thermal coefficient of resistance, low noise characteristics were implemented. Then MDTF were made in a vacuum deposition method. And MDTF for the analysis of the physical properties of silicon wafers were fabricated, TCR (temperature coefficient of resistance) value was made in order to measure the glass wafer and FT-IR (Fourier Transform Infrared spectroscopy) values were made in order to measure the germanium window. The analyzed results of MDTF -3 [%/K] has more characteristics of the TCR. And 8~12 um wavelength region close to 70% in the absorption characteristic.