• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.96-99
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• 1993

Electrical properties of the Thin Film Transistor(TFT) electrode metal films were investigated through the Test Elements Group(TEG) experiment. The main purpose of this investigation was to characterize the electrical resistance properties of patterned metal films with respect to the variations of film thickness and TEG metal line width. Aluminum(Al), Tantalum(Ta) and Chromium(Cr) that are currently used as TFT electrode films were selected as the probed metal films. To date, no work in the electrical characterizations of patterned electrodes of a-Si TFT was accomplished. Bulk resistance$(R_b)$, sheet resistance$(R_s)$, and resistivities($\rho$) of TEG patterned metal lines were obtained. Electrical continuity test of metal film lines was also performed in order to investigate the stability of metallization process. Almost uniform-linear variations of the electrical properties with respect to the metal line displacements was also observed.

• Korean Journal of Materials Research
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• v.25 no.1
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• pp.16-20
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• 2015

In this study, in order to improve the efficiency of n-type monocrystalline solar cells with an Alu-cell structure, we investigate the effect of the amount of Al paste in thin n-type monocrystalline wafers with thicknesses of $120{\mu}m$, $130{\mu}m$, $140{\mu}m$. Formation of the Al doped $p^+$ layer and wafer bowing occurred from the formation process of the Al back electrode was analyzed. Changing the amount of Al paste increased the thickness of the Al doped $p^+$ layer, and sheet resistivity decreased; however, wafer bowing increased due to the thermal expansion coefficient between the Al paste and the c-Si wafer. With the application of $5.34mg/cm^2$ of Al paste, wafer bowing in a thickness of $140{\mu}m$ reached a maximum of 2.9 mm and wafer bowing in a thickness of $120{\mu}m$ reached a maximum of 4 mm. The study's results suggest that when considering uniformity and thickness of an Al doped $p^+$ layer, sheet resistivity, and wafer bowing, the appropriate amount of Al paste for formation of the Al back electrode is $4.72mg/cm^2$ in a wafer with a thickness of $120{\mu}m$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.3-4
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• 2006

In this paper, a nickel silicide technology with post-silicidation annealing effect for thin film SOI devices is investigated in detail. Although lower resistivity Ni silicide can be easily obtained at low forming temperature, poor thermal stability and changing of characteristic are serious problems during the post silicidation annealing like ILD (Inter Layer Dielectric) deposition or metallization. So these effects are observed as deposited Ni thickness differently on As doped SOI (Si film 30nm). Especially, the sheet resistance of Ni thickness deposited 20nm was lower than 30nm before the post silicidation annealing. But after the post silicidation annealing, the sheet resistance was changed. Therefore, in thin film SOI MOSFETs or Ni-FUSI technology that the Si film is less than 50nm, it is important to decide the thickness of deposited Ni in order to avoid forming high resistivity silicide.

• Polymer(Korea)
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• v.38 no.3
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• pp.307-313
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• 2014

The physical properties of functionalized graphene sheet (FGS)/poly(ethylene-co-vinyl acetate) (EVA) was examined with various kinds of EVA, having vinyl acetate (VA) contents in the range of 0 to 40 wt%. The compatibility between FGS and EVA was enhanced as the polar VA content of EVA increased. Thus, the dispersion of FGS in EVA became finer, and the decrease of surface resistivity and the increase of tensile modulus by the added FGS became more effective when the VA content of EVA was high. When the VA content was low, the elongation at break was reduced drastically by added FGS due to the poor adhesion of FGS/EVA interface. The crystallization of EVA was generally retarded by the interaction with dispersed FGS. However, when both the VA content of EVA and the added amount of FGS were low, the crystallization of EVA was enhanced, probably due to the predominant nucleating effect by FGS.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.969-973
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• 2009

In this study, the electrical and optical properties of $(SiO_2)_x(ZnO)_{100-x}$ (SZO) films prepared on the coming 7059 glass substrates by using rf-magnetron sputtering method are investigated. The deposition rate becomes maximum near 3 wt.% and gradually decreases when the $SiO_2$ content further increases. The growth rates of the SZO film with $SiO_2$ content of 3 wt.% is $4\;{\AA}/s$. We found that the average transmittance of all films is over 80% in the wavelength range above 500 nm. The optical band gap were decreased from 3.52 to 3.33 eV as an increase the deposition thickness. X-ray diffraction patterns showed that the film with a relatively low $SiO_2$ content (< 4 wt.%) is amorphous. SZO film with the $SiO_2$ contents of 2 wt.% showed the resistivity of about $3.8{\times}10^{-3}\;{\Omega}{\cdot}cm$. The sheet resistance decreases with increasing the heat treatment temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1564-1567
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• 2005

Zinc oxide thin films were grown at the t emperature of $100^{\circ}C$ and $150^{\circ}C$ by means of plasma enhanced atomic layer deposition (PEALD) and conventional atomic layer deposition for applying to the transparent thin film transistor (TTFT). The growth rate of $1.9{\AA}/cycle$ with oxygen plasma is similar to that of film grown with water. While the sheet resistivity of ZnO grown with water is 1233 ohm/sq, that of film grown with oxygen plasma was too high to measure with 4 point probe and hall measurement system. The resistivity of the films grown with oxygen plasma estimated to be $10^6$ times larger than that of the films grown with water. The difference of electrical property between two films was caused by the O/Zn atomic ratio. We fabricated ZnO-TFT by means of ALD for the first time and the ZnO channel fabricated with water showed saturation mobility of $0.398cm^2/V{\cdot}s$ with bottom gate configuration.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1349-1351
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• 1998

Platinum-Cobalt alloy thin films were deposited on $Al_2O_3$ substrates by r.f. cosputtering for RTD temperature sensors. We made Pt-Co alloy resistance patterns on the $Al_2O_3$ substrates by lift-off method and investigated the physical and electrical characteristics of these films under various conditions (the input power, working vacuum, annealing temperature, thickness of thin films) and also after annealing these films. At input power of Pt : $4.4 W/cm^2$. Co:6.91W/$cm^2$. working vacuum of 10 mTorr and annealing conditions of $1000^{\circ}C$ and 60 min, the resistivity and sheet resistivity of Pt-Co thin films was $15{\mu}{\Omega}{\cdot}cm$ and $0.5{\Omega}/{\square}$, respectively. The TCR value of Pt-Co alloy thin films was measured with various thickness of thin films and annealing conditions. The optimum TCR value is gained under conditions $3000{\AA}$ of thin films thickness and $1000^{\circ}C$ of annealing temperature. These results indicate that Pt-Co alloy thin films have potentiality for the high resolution RTD temperature sensors.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1485-1487
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• 1997

Platinum-Cobalt alloy thin films were deposited on $Al_2O_3$ substrates by co sputtering for RTD temperature sensors. We made Pt-Co alloy resistance patterns on $Al_2O_3$ substrate by lift-off method and investigated the physical and electrical characteristics of these films under sputtering conditions (; the input power, working vacuum), annealing conditions (; temperature, time) and also after annealing these films. After the annealing treatment at $800^{\circ}C$ for 60min, the resistivity and sheet resistivity of Pt-Co thin films was $0.0302{\mu}{\Omega}{\cdot}cm$ and $0.1{\Omega}/{\square}$, respectively, and the TCR value of Pt-Co RTD was $3600ppm/^{\circ}C$ in the temperature range of $25{\sim}400^{\circ}C$. These results indicate that Pt-Co thin films have potential for the excellent RTD temperature sensors.

• Journal of Welding and Joining
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• v.29 no.5
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• pp.99-105
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• 2011

In this study, effect of Si content on nugget diameter in electric resistance spot welded dual-phase(DP) steel was investigated. The cold rolled DP steels with different Si content (0.5, 1.0, 1.5, 2.0 wt.%) were used and thickness of those sheet was 1.2mm. With increasing Si content, nugget diameter was increased at the same welding current. This is attributed to increase of heat input result from high resistivity. Also, nugget diameter was increased with an increase in Si content for the same heat input. For this reason, the melting point of DP steel is lowered with an increase in the Si content. And solid DP steel can easily be transformed to a liquid phase because the low melting point. Finally, a prediction formula for the nugget diameter(N.D.) could be obtained in terms of heat input(Q) and melting point(M.P) as follows: N.D.(mm) = 0.11Q(J) - 0.0031 M.P.($^{\circ}C$) + 0.32.

• Journal of Astronomy and Space Sciences
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• v.6 no.1
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• pp.1-15
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• 1989

Magnetospheic substorm in the magnetotail region is studied numerically by means of a three dimensional MHD code. The analytic solution for the quiet magnetotail is employed as an initial configuration. The localized solar wind is modeled to enter the simulation domain through the boundaries located in the magnetotail lobe region. As a result of the interaction between the solar wind and the magnetosphere, the magnetic field lines are stretched, and the plasma sheet becomes thinner and thinner. When the current driven resistivity is generated, magnetic reconnection is triggered by this resistivity. The resulting plasma jetting is found to be super-magnetosonic. Although the plasmoid formation and its tailward motion is not quite clear as in the two dimensional simulation, which is mainly because of the numerical model chosen for the present simulation, the rarification of the plasmas near the x-point is observed. Field aligned currents are observed in the late expansive stage of the magnetospheric substorm. These field aligned currents flow from the tail toward the ionosphere on the dawn side from the ionosphere to ward the tail on the dusk side, namely in the same sense of the region 1 current. As the field aligned currents develop, it is found that the cross tail current in the earth side midnight section of the magnetic x-point is reduced.