• Title/Summary/Keyword: dielectric function

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Dielectric Function Analysis of Cubic CdSe Using Parametric Semiconductor Model (변수화 반도체 모델을 이용한 Cubic Zinc-blonde CdSe의 유전함수 분석)

  • Jung, Y.W.;Ghong, T.H.;Lee, S.Y.;Kim, Y.D.
    • Journal of the Korean Vacuum Society
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    • v.16 no.1
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    • pp.40-45
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    • 2007
  • ZnCdSe alloy semiconductor was widely used for the optoelectronic device. And CdSe is the end-point in this material. In this work, we measured the dielectric function spectrum of cubic CdSe with Vacuum Ultra Violet spectroscopic ellipsometry and analysed this data with parametric model. As a result, we observed some of transition energy point over 6 eV and obtained the database for dielectric function spectrum, which could be used for temperature or alloy composition dependence study on optical property of CdSe.

A Study on Delay Time and Capacitance Calculation for Interconnection Line in Multi-Dielectric Layer (다층 유전체에서의 Interconnection Line에 대한 커패시턴스와 지연시간 계산 방법에 관한 연구)

  • 김한구;곽계달
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.9
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    • pp.46-55
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    • 1992
  • This paper propose how to calculate the capacitance for VLSI interconnection lines in multi-dielectric layer. The proposed method is a expansive form of 3-dimensional direct intergral method developed in single-dielectric layer. We took into consideration the effect of multi-dielectric layer by using additional boundary condition instead of modified Green's function. It is used the potential equations in line surface and the electric field equations in dielectric interface as the boundary condition. RC delay time for interconnection line of multi-dielectric layer is obtained from the calculated capacitance value. At this time, we are used Al and WSiS12T as interconnection materials.

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EM WAVE PENETRATION INTO A CYLINDRICAL CAVITY WITH A CENTER DIELECTRIC-ROD (중심의 유전체 막대가 있는 원통형공동의 전자파흡수)

  • Cho, Chul;Rhee, Un-Dong
    • 전기의세계
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    • v.28 no.2
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    • pp.68-75
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    • 1979
  • The penetration of an electro-magnetic wave through an aperture in a cylindrical structure with a center dielectric-rod is investgated. By using a standard mode matching procedure, the electrical and magnetic fields in a cavity are determined as a function of position inside the cavity and frequency of the incident field. For the given parameters, computed data are obtained and the results exhibited in form of amplitude curves of the nor malized field and energy densities of functions of position and frequency. Depending on the increase of the relative dielectric constant of center dielectric-rod, the resonance frequecies of the cavity vary as the cavity size decrease. The stored electro-magnetic energy varies very rapidly as a function of position inside the cavity and of the source frequency. Its peak value can be two orders of magnitude greater than the incident energy density. The frequencies where the peaks occur can be identified approximately as the resonance frequencies of the cavity.

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Dielectric, Pyroelectric and Piezoelectric Properties of 0.7PMN-0.3PT Ceramics Modified With Cr$_2$O$_3$

  • Hyun, June-Won
    • Journal of the Korean institute of surface engineering
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    • v.36 no.5
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    • pp.413-417
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    • 2003
  • The effect of 0-0.7 ㏖% addition of $Cr_2$$O_3$on the dielectric, pyroelectric, and piezoelectric properties were studied in the (Mg$0.7Pb_{1}$$3/Nb_{2}$3/)$O_3$-$0.3PbTiO_3$(0.7PMN-0.3PT) ceramics with composition near the morphotropic phase boundary. The dielectric constant and loss of the ceramics samples were measured as a function of temperature at various frequencies (0.1-100 KHz). The pyroelectric coefficient was measured by using the Byer-Roundy method as a function of temperature. Dielectric, pyroelectric, and piezoelectric constant achieved the maximum values of 0.4 ㏖% $Cr_2$$O_3$The transition temperature is continuously shifted to lower temperature with an increase of a small amount of $Cr_2$$O_3$.

Optical Constants and Dispersion Parameters of CdS Thin Film Prepared by Chemical Bath Deposition

  • Park, Wug-Dong
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.4
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    • pp.196-199
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    • 2012
  • CdS thin film was prepared on glass substrate by chemical bath deposition in an alkaline solution. The optical properties of CdS thin film were investigated using spectroscopic ellipsometry. The real (${\varepsilon}_1$) and imaginary (${\varepsilon}_2$) parts of the complex dielectric function ${\varepsilon}(E)={\varepsilon}_1(E)+i{\varepsilon}_2(E)$, the refractive index n(E), and the extinction coefficient k(E) of CdS thin film were obtained from spectroscopic ellipsometry. The normal-incidence reflectivity R(E) and absorption coefficient ${\alpha}(E)$ of CdS thin film were obtained using the refractive index and extinction coefficient. The critical points $E_0$ and $E_1$ of CdS thin film were shown in spectra of the dielectric function and optical constants of refractive index, extinction coefficient, normal-incidence reflectivity, and absorption coefficient. The dispersion of refractive index was analyzed by the Wemple-DiDomenico single-oscillator model.

An Image Improvement for Microwave Diffraction Tomography under the Born Approximation Based on the Projection Function (Born 근사하에 투영함수를 이용한 초고주파 회절단층촬영의 영상개선)

  • 서경환;김상기;라정웅;김세윤
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.2
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    • pp.1-7
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    • 1992
  • A consideration for image improvement under the Born approximation in the microwave diffraction tomography is suggested by using a projection function. The limiting factors in the degrading reconstructed image due to Born approximation are identified in terms of projection function and its modification is suggested to improve the degraded image based upon the Born approximation. In order to verify the proposed method, the reconstructed images are shown by computer simulation from the back-scattered data of angular and frequency diversity for squared dielectric cylinder with a various relative dielectric constant. From simulation results, it was shown that the proposed method can lead to a fairly good improved image for a severe degraded one irrespective of homogeneous and inhomogeneous dielectric object. In the future, the analysis on the limitation of this method should be considered and performed by means of more quantitative method.

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A Study on Calculation of Capacitance Parameter for Interconnection Line in Multilayer Dielectric Media (다층 유전체 매질에서의 Interconnection Line에 대한 Capacitance Parameter 계산에 관한 연구)

  • 김한구;곽계달
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.8
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    • pp.1187-1196
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    • 1989
  • In this paper, a method for computing the capacitance parameter for a multi-interconnection line in a multilayered dielectric region is presented. The number of interconnection lines and the number of dielectric layers are arbitrary, and the interconnection lines are finite cross section or infinite cross section. The surface of lines and dielectric interface are divided into subsection. The surface charge density of each subsection is a constant step-pulse function for each subsection. After the solution of surface charge density is effected by the method of moments, capacitance parameter is calculated.

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The Design of Dielectric Ceramic Antenna for GPS (GPS 용 유전체 세라믹 안테나의 설계)

  • 김현철;노용래;김인태;김윤호
    • Journal of the Korean Ceramic Society
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    • v.33 no.9
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    • pp.977-984
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    • 1996
  • This paper analyzes the performance of a rectangular dielectric ceramic antenna by the theoretical cavity model such as input impedance resonant frequency quality factor efficiency and bandwidth. Through a compu-ter simulation variation of the antenna characteristics is found as a function of the antenna parametes. (permit-tivity permeability antenna size etc) Based on the results we propose a new design method for the dielectric ceramic antenna to be employed in Global Positioning Systems.

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Dielectric and Optical Properties of Amorphous Hafnium Indium Zinc Oxide Thin Films on Glass Substrates

  • Shin, Hye-Chung;Seo, Soon-Joo;Denny, Yus Rama;Lee, Kang-Il;Lee, Sun-Young;Oh, Suhk-Kun;Kang, Hee-Jae;Heo, Sung;Chung, Jae-Gwan;Lee, Jae-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.225-225
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    • 2011
  • The dielectric and optical properties of GaInZnO (GIZO), HfInZnO (HIZO) and InZnO (IZO) thin films on glass by RF magnetron sputtering method were investiged using reflection electron energy loss spectroscopy (REELS). The band gap was estimated from the onset values of REELS spectra. The band gaps of GIZO, HIZO and IZO thin films are 3.1 eV, 3.5 eV and 3.0 eV, respectively, Hf and Ga incorporated into IZO results in an increase in the energy band gap of IZO by 0.5 eV and 0.1 eV. The dielectric functions were determined by comparing the effective cross section determined from experimental REELS with a rigorous model calculation based on the dielectric response theory, using available software package, good agreement between the experimental and fitting results gives confidence in the accuracy of the determined dielectric function. The main peak of Energy Loss Function (ELF) obtained from IZO shows at 18.42 eV, which shifted to 19.43 eV and 18.15 eV for GIZO and HIZO respectively, because indicates the corporation of cation Ga and Hf in the composition. The optical properties represented by the dielectric function e, the refractive index n, the extinction coefficient k, and the transmission coefficient, T of HIZO and IZO thin films were determined from a quantitative analysis of REELS. The transmission coefficient was increased to 93% and decreased to 87% in the visible region with the incorporation of Hf and Ga in the IZO compound.

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Dielectric Properties of Polymer-ceramic Composites for Embedded Capacitors

  • Yoon, Jung-Rag;Han, Jeong-Woo;Lee, Kyung-Min
    • Transactions on Electrical and Electronic Materials
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    • v.10 no.4
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    • pp.116-120
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    • 2009
  • Ceramic-polymer composites have been investigated for their suitability as embedded capacitor materials because they combine the processing ability of polymers with the desired dielectric properties of ceramics. This paper discusses the dielectric properties of the ceramic ($BaTiO_3$)-polymer (Epoxy) composition as a function of ceramic particle size at a ceramic loading of 40 vol%. The dielectric constant of these ceramic-polymer composites increases as the powder size decreases. Results show that ceramic-polymer composites have a high dielectric constant associated with the $BaTiO_3$ powder with a 200 nm particle size, high insulation resistance, high breakdown voltage (> 22 KV/mm), and low dielectric loss (0.018-0.024) at 1 MHz.