• Title, Summary, Keyword: Substrate dependence

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Effect of Out-of-plane Retardation of Substrate Film on the Viewing-angle Dependence of Transmittance in a Display Device

  • Ahn, Sumin;Lee, Ji-Hoon
    • Current Optics and Photonics
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    • v.5 no.1
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    • pp.45-51
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    • 2021
  • The effect of the out-of-plane retardation (Rth) of a substrate film on the viewing-angle dependence of transmittance (TR) in a display device was investigated. When the polarization state of input light deviates from the transmission axis of the polarizer, Rth of the substrate film induces inhomogeneous viewing-angle dependence of TR. The inhomogeneity of TR gets worse for greater values of of Rth. The inhomogeneous TR profile can be eliminated by inserting compensation films, which convert the input polarization state to the linear polarization state parallel to the transmission axis of the polarizer.

Substrate Doping Concentration Dependence of Electron Mobility Enhancement in Uniaxial Strained (110)/<110> nMOSFETs

  • Sun, Wookyung;Choi, Sujin;Shin, Hyungsoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.5
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    • pp.518-524
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    • 2014
  • The substrate doping concentration dependence of strain-enhanced electron mobility in (110)/<110> nMOSFETs is investigated by using a self-consistent Schr$\ddot{o}$dinger-Poisson solver. The electron mobility model includes Coulomb, phonon, and surface roughness scattering. The calculated results show that, in contrast to (100)/<110> case, the longitudinal tensile strain-induced electron mobility enhancement on the (110)/<110> can be increased at high substrate doping concentration.

Substrate Temperature Dependence of Microcrystalline Silicon Thin Films by Combinatorial CVD Deposition

  • Kim, Yeonwon
    • Journal of the Korean institute of surface engineering
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    • v.48 no.3
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    • pp.126-130
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    • 2015
  • A high-pressure depletion method using plasma chemical vapor deposition (CVD) is often used to deposit hydrogenated microcrystalline silicon (${\mu}c-Si:H$) films of a low defect density at a high deposition rate. To understand proper deposition conditions of ${\mu}c-Si:H$ films for a high-pressure depletion method, Si films were deposited in a combinatorial way using a multi-hollow discharge plasma CVD method. In this paper the substrate temperature dependence of ${\mu}c-Si:H$ film properties are demonstrated. The higher substrate temperature brings about the higher deposition rate, and the process window of device quality ${\mu}c-Si:H$ films becomes wider until $200^{\circ}C$. This is attributed to competitive reactions between Si etching by H atoms and Si deposition.

The Dependence of Substrate on Ag Photodoping into Amorphous GeSe Thin Films using Holographic Method (비정질 GeSe 박막으로의 은-광도핑에 대한 기판의존성)

  • Yeo, Jong-Bin;Yun, Sang-Don;Lee, Hyun-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.10
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    • pp.852-858
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    • 2007
  • The dependence of substrate on the Ag photodoping phenomenon into amonhous $({\alpha}-)$ GeSe thin film has been investigated using holographic method. A 442 nm HeCd laser was utilized as a light source for the holographic exposure and a 632.8 nm HeNe laser to measure the variation of diffraction efficiency $(\eta)$ in real time. The films (Ag and ${\alpha}-GeSe$) were thermally deposited on the substrates, i.e. p-type Si(100), n-type Si(100) and slide glass. The sample structures prepared were two types: type I (Ag/${\alpha}$-SeGe/substrate) and type II (${\alpha}$-SeGe/Ag/substrate). The $\eta$ kinetics comprised to be three steps in which $\eta$ initially increases, is saturated to be maximized $(\eta_M)$, and then decreases relatively gradually. For the same substrate, the $\eta_M$ values of the type II were higher than those of type I. In addition, the type II exhibited the highest $\eta_M$ for p-type Si substrate, while that in type I was observed for n-type Si substrate. These tendency is explained by the diffusion of minority carrier in the films and the change of magnitude and direction in internal fields generated at the film interfaces. Atomic-force-microscope (AFM) was used to observe relief-type grating patterns.

A New Method for Extracting Interface Trap Density in Short-Channel MOSFETs from Substrate-Bias-Dependent Subthreshold Slopes

  • Lyu, Jong-Son
    • ETRI Journal
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    • v.15 no.2
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    • pp.11-25
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    • 1993
  • Interface trap densities at gate oxide/silicon substrate ($SiO_2/Si$) interfaces of metal oxide semiconductor field-effect transistors (MOSFETs) were determined from the substrate bias dependence of the subthreshold slope measurement. This method enables the characterization of interface traps residing in the energy level between the midgap and that corresponding to the strong inversion of small size MOSFET. In consequence of the high accuracy of this method, the energy dependence of the interface trap density can be accurately determined. The application of this technique to a MOSFET showed good agreement with the result obtained through the high-frequency/quasi-static capacitance-voltage (C-V) technique for a MOS capacitor. Furthermore, the effective substrate dopant concentration obtained through this technique also showed good agreement with the result obtained through the body effect measurement.

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Temperature Dependence Change of Electrical Resistivity on PdHx Films due to Film Thickness Change (PdHx 박막의 두께 변화에 의한 전기비저항의 온도 의존성 변화)

  • Cho, Young-sin
    • Transactions of the Korean hydrogen and new energy society
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    • v.6 no.1
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    • pp.17-22
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    • 1995
  • Thermally evaporated Pd films on substrate were hydrogenated upto 1 bar of hydrogen gas at room temperature. Temperature dependence hange of electrical resistivity on Pd films is examined in the thickness range between $60{\AA}$ and $990{\AA}$. Resistivity of Pd is fitted well with Bloch-$Gr{\ddot{u}}neisen$ formula. Debye temperatures of Pd films are about 254 K, which are 20 K lower than that of bulk Pd. Debye temperature is not sensitive to film thickness change. Temperature of substrate during evaporation changes temperature dependence of resistivity of films much. Optical phonon contribution increases with decreasing temperature of PdHx.

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Athermalized Polymeric Arrayed-Waveguide Grating by Partial Detachment from a Si Substrate

  • Lee, Jong-Moo;Ahn, Joon-Tae;Park, Sun-Tak;Lee, Myung-Hyun
    • ETRI Journal
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    • v.26 no.3
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    • pp.281-284
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    • 2004
  • We demonstrate a new fabrication method for adjusting the temperature dependence of a polymeric arrayed-waveguide grating (AWG) on a Si substrate. A temperature-dependent wavelength shift of-0.1nm/$^{\circ}C$ in a polymeric AWG on a Si substrate is reduced of+0.1nm/$^{\circ}C$ by detaching part of the polymer film, including the grating channel region of the AWG, from the Si substrate while the other parts remain fixed on the substrate.

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Distinctive pH Dependence and Substrate Specificity of Peptide Hydrolysis by Human Stromelysin-1 (Stromelysin-1에 의한 펩타이드 가수분해에서 pH와 기질특이성 연구)

  • ;Marianne V. Sorensen
    • Journal of Life Science
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    • v.10 no.2
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    • pp.210-217
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    • 2000
  • A kinetic profile of the catalytic domain of stromelysin-1 (SCD) using the fluorescent peptide substrate has been determined by the stopped-flow technique. The pH profile has a pH optimum of about 5.5 with an extended shoulder above pH 7. Three pKa values, 5.0, 5.7, and 9.8 are found for the free enzyme state and two pH independent Kcat/Km values of 4.1$\times$104 M-1 s-1 and 1.4$\times$104 M-1 s-1 at low and high pH, respectively. The profile is quite different in shape with other MMP family which has been reported, having broad pH optimum with two pKa values. The substrate specificity of SCD towards fluorescent heptapeptide substrates has been also examined by thin layer chromatography. The cleavage sites of the substrates have been identified using reverse-phase HPLC method.SCD cleaves Dns-PLA↓L↓WAR and Dns-PLA↓L↓FAR at two positions. However, the Dns-PLA↓LRAR, Dns-PLE↓LFAR, adn Dns-PLSar↓LFAR are cleaved exclusively at one bond. The double cleavages of Dns-PLALWAR and Dns-PLALFAR by SCD are in marked contrast to the close structurally related matrilysin. A notable feature of SCD catalysis agrees with the structural data that the S1' pocket of SCD is deeper than that of matriysin. The differences observed between SCD and matrilysin may form the basis of understanding the structural relationships and substrate specificities of the MMP family in vivo.

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An Effect of $O_2/Ar$ Ratio on the Characteristics of RF Magnetron Sputtered $BaTiO_3$ Thin Film (RF Magnetron Sputtering법으로 $BaTiO_3$ 박막 증착시 $O_2/Ar$비가 박막의 특성에 미치는 영향)

  • 안재민;최덕균;김영호
    • Journal of the Korean Ceramic Society
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    • v.31 no.8
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    • pp.886-892
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    • 1994
  • Structural and electrical properties of BaTiO3 thin films deposited on Pt/SiO2/Si substrates by RF magnetron sputtering method have been investigated. Crystallization behavior and electrical properties were studied for the films deposited under various sputtering gas compositions (Ar+O2 gas mixture) and substrate temperatures. All the films deposited above 50$0^{\circ}C$ were all crystallized and their preferred orientation changed from (001) to (111) with the addition of oxygen gas. The dielectric constant of films deposited in pure argon was about 110 and showed little dependence on the substrate temperature. But that was increased as the ratio of O2/Ar increased and its substrate temperature dependence was discernible. The highest dielectric constant reached to 550. In addition, the films deposited in mixed gas showed stable dielectric properties against the frequency and temperature.

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Thickness Dependence of the Crystallization of FePt/MgO(001) Magnetic Thin Films (FePt/MgO(001) 자성박막 결정화의 두께의존성)

  • Jeung, Ji-Wook;Yi, Min-Soo;Cho, Tae-Sik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.2
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    • pp.153-158
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    • 2010
  • The crystallization of FePt/MgO(001) magnetic thin films of various thicknesses has been studied using synchrotron x-ray scattering, atomic force microscope, and vibrating sample magnetometer. In film with a 499-$\AA$-thick, face-centered tetragonal, ordered FePt phase was dominantly crystallized into perpendicular (001) grains keeping the magnetically easy c-axis normal to the film plane during annealing. In film with a 816-$\AA$-thick, however, longitudinal (110) grains keeping the c-axis parallel to the film plane were grown on top of the perpendicular (001) grains. The behavior of the magnetic properties was consistent with the thickness dependence of the crystallization. We attribute the thickness dependence of the crystallization to the substrate effect, which prefers the growth of the c-axis oriented perpendicular grains near the film/substrate interfacial area.