In this study, ruin films of Octla-dodecyloxy copper-phthalocyanine were prepared by Langmuir-Blodgett (LB) method and characterirzed by using UV-Vis absorption spectroscopy and ellipsometry. [1],r[2] Optimal transfer condition of LB films was investigated and preliminary results of current-voltage(1-V) characteristics of these films exposed to NO$_2$ gas as were discussed functions of film thickness, temperature and NO$_2$ gas concentration.

A study on the electrical conduction characteristics of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir- Blodgett(LB) technique has recently been attracted interest as a method of the deposition ultrathin films. We hate fabricated N-docosyl N\`-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the molecular orientation and electrical conduction characteristics. We have measured infrared transmission-reflection spectra. The alkyl chain is found to he well-ordered with the tilt angle of 13$^{\circ}$ with respect to the substrate surface normal and the TCNQ plane is tilted at 76$^{\circ}$ the surface normal. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on the incident angle, which indicates conducting species change. The in-plane conductivity of 31 lagers is approximately 1.33$\times$10$^{-6}$ S/cm. The ohmic behaviour was observed below 0.6 V, when current-voltage(I-V) characteristics was measured verically.

The fabrication and performance of a thin film pressure sensor are described. Cu-Ni thin film strain gauges have been fabricated by RF magnetron sputtering. For all the gauges, the relative chance in resistance ΔR/R with pressure is of the order 10$^{-3}$ for the maximum pressure. The output characteristic is found to be linear over the entire Pressure range (0-30kgf/cm$^2$) and the output sensitivity is 1.6 mV/V. The maximum nonlinearity observed in output characteristics is 0.34%FS for 5V excitation and the hysteresis is less than 0.1%FS.

In this paper, the voltage step-up ratio, efficiency and input impedance of the PMN-PZT cert- mic transformer(PT) were investigated for the variation of resonant frequency according to lead resistance. The output voltage and voltage step-up ratio are increased with the the increase of load resistance. The efficiency of PT showed the maxinum value of 91% at R$_{L}$ of 500k$\Omega$X>

Ferroeletric LiNbO$_3$ thin films hale been prepared directly on Si(100) substrates by conventional RF magnetron spurttering system for nonvolatile memory applications. As-deposited films were performed RTA(Rapid Thermal Annealing) treatment in an oxygen atmosphere at 600 $^{\circ}C$ for 60 s. The rapid thermal annealed films were changed to poly-crystalline ferroelectric nature from amorphous of as-deposition. The resistivity of the ferroelectric LiNbO$_3$ film was increased from a typical vague of 1~2$\times$10$^{8}$ $\Omega$.cm before the annealing to about 1$\times$10$^{13}$ $\Omega$.cm at 500 kV/cm and reduce the interface state density of the LiNbO$_3$/Si(100) interface to about 1$\times$10$^{11}$ cm$^2$ . eV. Ferroelectric hysteresis measurements using a Sawyer-Tower circuit yielded remanent polarization (Pr) and coercive field (Ec) values of about 1.2 $\mu$C/cm$^2$ and 120 kV/cm, respectively.

Capacitor-type MONOS (metal-oxide-nitride-oxide- semiconductor) NVSMs with 23$\AA$ tunneling oxide and 40$\AA$ blocking oxide were fabricated. The thicknesses of nitride layer were 45$\AA$, 91$\AA$ and 223$\AA$, Breakdown characteristics of MONOS devices were measured to investigate the reliability of superthin ONO structure using ramp voltage and constant voltage method. Reducing the nitride thickness will significantly increase the reliablity of MONOS NVSM.

In this paper, we studied the variation in optical constants of Te-doped G $e_{15}$ /$Sb_{85}$ thin films with 7800$\AA$ diode-laser exposing time and power. The reflectances were increased with the increase of laser exposure time and the laser power in all films. Also, the refractive indices of the films after exposing were higher than those of the as-deposited films. Thus, the fast crystallization was caused by addition to the more Te content at the lower lacer power. It was observed that the surface morphologies of the exposed films are higher than those of the as-deposited films by SEM analysis. Therefore, it is considered that the T $e_{0.5}$(G $e_{15}$ /$Sb_{85}$)$_{99.5}$ thin films will show the high contrast ratio and high SNR and have fast erasing time due to crystallization when these films is applied to optical recording materials.terials.s.

The linear dichroism in obliquely deposited amorphous As$_{40}$ /Ge$_{10}$/Se$_{15}$ /S$_{35}$ thin films has been studied using a sub-bandgap exposure by He-Ne laser. As increasing the deposition angle, the magnitude of 야chroism in as-deposited thin films was enhanced to about 10%, while that of the films annealed abode T$_{g}$ before illumination was nut enhanced at all.l.l.l.l.

Effects of B$_2$O$_3$ addition in the Li$_2$O-MgO-MgF$_2$-SiO$_2$g1ass system were investigated in order to make glass-ceramics for low temperature firing substrate. Base glass was made by melting at 145$0^{\circ}C$ . This glass was analyzed by THA and DTA to settle nucleation and crystallization temperature. After crystallization. crystal phase and microstructure were absorvated by XRD and SEM. Glass powders were made by water swelling method. Average particle size was 5.44${\mu}{\textrm}{m}$

In spite of the addtion of Zn, a high quality of Zn-doped GaN film were prepared. The growth rates of Zn-doped GaN films were varied from 0.14${\mu}{\textrm}{m}$/min to 0.05${\mu}{\textrm}{m}$/min according to the amount of Zn incorporated, The smallest value of the FWHM of x-ray rocking curve was 407 arcsec. The Zn-related Photoluminescence emission peaks which occurred at 2.927 and 2.824 eV shifted toward the low energy region by increasing Zn partial pressures. It was compared between the intensities of D-A pair (3.259eV) and that of the exciton bound to acceptor band(E$_{x-A}$=3.449eV).).

(Pb. La)TiO$_3$ thin films were fabricated by sol-gel Processing and spin-coated on the Pt substrate. The spin-coated PLT films were sintered at 75$0^{\circ}C$ for 5min by rapid thermal ann La content dependence of the electrical properties of the PLT thin films are discussed. Wit La mole% from 20 to 36mo1e%. the dielectric constant of the PLT thin films decreased f 570. P-E hysteresis loops changed from ferroelectric to paraelectric. and the charge storage charging time decreased. The Curie Point decreased with increasing La content. The leak density also decreased and La 36mo1% species shows mood characteristics less than 10- electric field 500 (KV/cm) Because of the broad range of composition-controlled ferroelectric PLT thin films are suitable for memory application.

In this study, PLZT stock solutions were prepared by sol-gel processing to fabricate PLZT thin films. The stock solutions were spin-coated on ITO-glass and the film were annealed by rapid thermal annealing(RTA). The variation of tile crystallographic structure of the thin films and the phase transition with respect to it were observed using Raman spectra. Raman result showed that the band of spectra are broad as the amount of Zr substitution increased and specially, abrupt change occurs in the raman spectra upon crossing the tetragonal-rhombohedral phase boundry at 2/55/45 PLZT thin film. So, the fact that the crystallographic structure was transitted from tetragonal to rhombohedral structure was certified.

SAW filters of transversal type were fabricated on some piezoelectric substrates of the LN 128$^{\circ}$ Y-X, LN 64$^{\circ}$Y-X, Quartz ST-cut wafers through the simulation in which the number o: IDT and window function were changed for the required frequency, and the mask making. Their IDT spacing and width were 3 ${\mu}{\textrm}{m}$, chip size was 4.462 $\times$ 2.086 mm$^2$, and they had double electrode transversal type IDTs. In addition to pure Al electrode devices, Ti thin films having the different thicknesses was introduced between the Al electrode and the substrate for improving the power resistance strength. They had 11-12 dB insertion losses similar to those of pure Al electrode SAW filters in case of LN 128$^{\circ}$ Y-X, LN 64$^{\circ}$ Y-X, meaning that Ti thin film was not detrimental to the insertion loss and general frequency properties. The filters had the center frequencies 162MHz for LN 128$^{\circ}$ Y-X, 186MHz for 64$^{\circ}$ Y-X, and 131MHz for Quartz ST-cut substrates.

Dieletric ailed piezoelectric properties of Pb[$Zr_{0.45}$/ $Ti_{0.5-x}$/L $u_{x}$ (M $n_{1}$3//S $b_{2}$3)$_{0.05}$] $O_3$(0$\leq$x $\leq$0.03) were investigated. The partial substitution of $Ti^{4+}$ by a L $u^{3+}$ permitted improvement of the piezoelectric constant( $d_{33}$ ), electromechanical coupling factor ( $k_{p}$ ) and dielectric constant($\varepsilon$$_{33}$ /Sup T/). The dielectric loss(tan $\delta$ ) increased and mechanical quality factor(Qm) decreased with an increase of x were observed. A new piezoelectric material for actuator application was developed at x=0.02 with $d_{33}$ =370$\times$10$^{-2}$ /C/N, $k_{p}$ =58.5%, $\varepsilon$$_{33}$ $^{T}$ =1321, $Q_{m}$ =714 and tan $\delta$ =0.98%.%..%.%.

Microwave dielectric properties of A1$_2$O$_3$ ceramics resonator were investigated with impurity addition. Increasing the contents of Bi$_2$O$_3$Q-value and Q $\times$ f were increased. In the specimen with the content of Bi$_2$O$_3$(0.3wt%), dielectric constant, quality factor and temperature coefficient of resonant frequency(TCRF, $\tau$$_{f}$) had a good values of 10.76,23,253(at 9.68[GHz]) and -39.09(ppm/$^{\circ}C$), respectively. The TCRF value was decreased with MnO$_2$ and increased with Sm$_2$O$_3$. La$_2$O$_3$.>.

In this paper, to obtain the YbB $a_2$C $u_3$ $O_{x}$ superconductor, the mixed Powders of Y $b_2$ $O_3$, BaC $O_3$, CuO and Y $b_2$BaCu $O_{5}$, BaCu $O_2$ were used and the various calcining conditions were applied for the 123 phase of YbB $a_2$C $u_3$ $O_{x}$. Samples were prepared by the mixed oxide method and calcined with various temperatures of 88$0^{\circ}C$ ~91$0^{\circ}C$ . It was observed that the distribution of YbB $a_2$C $u_3$ $O_{x}$ phase which was calcined at 90$0^{\circ}C$ for 12 hours and 99 hours. But the result of long time calcination(99 hrs), the 123 phase of YbB $a_2$C $u_3$ $O_{x}$ was existed between 89$0^{\circ}C$ and 91$0^{\circ}C$ . And the best case could be obtained at the calcination temp. of 90$0^{\circ}C$ from the mixed Powder of YbB $a_2$C $u_3$ $O_{5}$ and Bacu $O_2$ which were prepared individually.idually.

A low loss x-cut LiNbO$_3$ optical waveguide was fabricated by Ti in-diffusion and the guided-mode properties and total insertion loss of pigtailing with polarization maintaining fiber(PMF) were investigated and measured at optical wavelength 15507. For formaing the waveguide, the parameters of diffusion Ti thickness, waveguide line-width, length, diffusion temperature, time and atmosphere were set 1400$\AA$, 8${\mu}{\textrm}{m}$, 3.3cm, 105$0^{\circ}C$, 8 hours and wet bubbled oxygen, respectively. and then After the polishing and pigtailing, it showed that total insertion loss was -4.1dB for TM mode, -5.5dB for TE mode, and mode size, that is, horizontal/vertical sizes were 13.87/18${\mu}{\textrm}{m}$ for TM mode, 9.61${\mu}{\textrm}{m}$/6.5${\mu}{\textrm}{m}$ for TE mode.

A 5Gbps LiNb $O_3$ optical phase modulator was packaged and described. A APE(annealed proton exchange) method was employed for the optical waveguide and the electrode of ACPS (asymmetric coplanar strip) type was formed by electro-plating on LiNb $O_3$ fort applying microwave signal. The resulted phase modulator exhibited a single mode at a 1550nm wavelength and Its modulation bandwidth, Insertion loss and driving voltage showed 7$^{GHz}$, 3. $O^{dB}$ and 6V. respectively.y.

In this experiment, A1$_2$O$_3$ thick films were prepared by electrophoretic method using A1$_2$O$_3$ fine Powder of which composition were FA-5-500 and FA-5-900. The growth behavior of A1$_2$O$_3$ thick films were characterized as preparation conditions, such as applied voltage, deposition time and adding conditions. As a result, A1$_2$O$_3$ thick films were successfully fabricated by electrophoretic method on molybdnum plate in which etanol and distilled used were used as a solvent. Deposition conditions for good uniformity of the A1$_2$O$_3$ thick films were applied voltage of 60volts, deposition time of 2 seconds, heat treatment at 1$700^{\circ}C$ for 5 minutes.

A microstructure of realistic ZnO varistor was constructed by Voronoi network and studied cia computer simulation. The grain size and standard deviation was calculated with new method and have good agreement with experimental data. In this network, the grain boundary conditions of three different type are randomly distributed. The three electrical boundary conditions . (1) type A junctions (high nonlinearity); (2) type B junctions (low nonlinearity); (3) type C junctions (linear with low-resistivity) are fitted from the experimental measurement. The electrical properties were studied by varying the boundary type concentration and the disorder parameter d. The shape of I-V characteristic curve of the network is affected by the type concentration and the disorder parameter has an effect on the double inflected region.

고주파 반응성 스퍼터링 방법을 사용하여 희토류가 첨가된 SiO$_2$ 박막을 제작하여 특성을 조사하여, 양질의 희토류 원소가 첨가된 SiO$_2$ 박막의 최적의 제작조건을 도출하고 Er-Al:SiO$_2$ 박막의 소자웅용 가능성에 대하여 조사하였다 열처리전의 Er의 농도는 EDS(Energy dispersing x-ray spectrometer)로 측정한 결과 0.77% 로 농도를 나타내었고 코아층 첨가된 Er은 균일하게 분포되었다 크레드층의 굴절률은 633nm의 파장에서 측정하였을때 1.458이였고 코아층의 굴절률은 동일 파장에서 1.757이였다. 굴절률 분포도 (Refractive Index Profile)는 계단형 굴절률 분포로 코아층/클래드 굴절률 차 $\Delta$n$_{ESI}$ = 0.1였다.

We investigated the sheet resistance properties of tungsten nitride thin films deposited by RF and DC sputtering system. It deposited at various conditions that determine the sheet resistance. The properties of the sheet resistance of these films were measured under various conditions. Sheet resistance analysed under the flow rate of the argon gas and contents of nitrogen from nitrogen-argon gas mixtures. We found that these sheet resistance were largely depend on the temperature of substrate, gas flow rate and RF power. Very high and low sheet resistance of tungsten films obtained by DC sputtering. As the increase of contents of nitrogen gas obtained from nitrogen-argon gas mixture, tungsten nitride thin films deposited by the reactive DC sputtering and the sheet resistance of these films were increased.

The nonuniformity of electrical characteristics of grain boundaries in ZnO varistors wei\ulcorner systematically analyzed. The high nonuniformity exist in barrier voltages and nonlinearity coefficients among different grain boundaries. The barrier voltages have normal distributions, only a few grain boundaries were electrically active, and the grain boundaries can be simply classified into good, bad, and ohmic ones according to the electrical characteristics of grain boundaries. The average barrier voltage is equal to 3.3 V by direct method, but it is only 2.3 V by indirect method. There is a high difference between the barrier voltages by direct and indirect measurement methods. The A1$_2$O$_3$ dopants affect the electrical characteristics of grain boundaries by changing the electron status In grain boundary and intragrain.

The thickness dependence of stress voltage oxide currents has been measured in oxides with thicknesses between 10nm and 80nm. The oxide currents were shown to be composed of stress current and transient current. The stress current was caused by trap assited tunneling through the oxide. The transient current was caused by the tunneling charging and discharging of the trap in the interfaces. The stress current was used to estimate to the limitations on oxide thicknesses. The transient current was used to the data retention in memory devices.

In this paper, the breakdown strength of Pure HDPE(High density polyethylene) films and aged HDPE films were evaluated using 2-parameter Weibull distribution function. The result show that both were fitted 2-parameter Weibull distribution. This method could be used to be the diagnostic tool to evalute the insulation performance and endurance under the multiple stresses.

In this paper, we have evaluated temperature, electric field, Pressure dependency and dielectric properties of EPDM XLPE and EPDM/XLPE\`s interface. Temperature dependency of EPDM had great influence with dielectric properties, but pressure and applied voltage of EPDM had no effect on dielectric properties. Dielectric properties of XLPE were influenced by not only temperature but also pressure and applied voltage. We knowed that dielectric properties of EPDM/XLPE were trended toward tendency of those of EPDM

In this paper, we investigated the liquid crystal(LC) alignment and generation of pretilt angle by using photo-alignment techniques on two kinds of polyimide(Pl) surface. It was found that the uniform alignment for nematic(N) LC is obtained in a cell with slanted UV light irradiation on PI surface without side-chain. We successfully observed that the pretilt angle of NLC is generated about 3.3 degrees in a cell with an incidence angle of 70 degrees on PI surface without side chain. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecular and the polymer.

In this paper A double-layer organic electroluminescent(EL) device was fabricated using a TPD(N,N'-dipheny] -N,N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4.4'-diamine: aromatic diamine), as a hole-transport material and tris (8-hydroxy quinolinate) aluminum(Alq$_3$) as a an emiting material and its performance characteristics were investigated. structure of devices is ITO/TPD/Alq$_3$/Al. we have fabricated hole transport layer of two types. Doping material of Hole Transport material is Poly(methyl methacrylate)(PMMA) and PEI(Poly-Ether-Imide). Carrier injection from the electrodes to the doped PMMA and PEI layer through the dopants and concomitant electroluminescence from Alq$_3$were observed. Green emission with luminance of 40cd/m$^2$was achieved at a drive voltage of 30V

In this paper, we deal with the effect on magnetic properties when Nd is added to Sr ferrite bonded magnet. First, we choose SrO$_{n}$.Fe$_2$O$_3$(n=5.9), which is nonstoichiomatric composition, as specimen ferrite. Then, we add 5wt% polyvinyl alcohol and calcinate at 12$25^{\circ}C$ under $N_2$ environment for carbon coating on chemical compound specimen. After that we obtain 1.2${\mu}{\textrm}{m}$ single domain powder through grinding process for 18 hours. The single domain Sr ferrite Powder is well mixed with silage coupling and calcium stearate of 1wt% Then, it is kneaded by using polyamide12 as a binder and is pelleted. After adding Nd-Fe-B powder to the pelleted specimen, we injection-mould it under magnetic field by using anisotropic mould. Especially, when we add l3wt% Nd-Fe-B powder to the polyamide12, we obtain excellent magnetic propertiecs which are $_{B}$H$_{C}$=2.65KOe, Br=3.16KG and (BH)$_{max}$=2.61MGOeOeOeOeOe

The magnetic properties of calcined Sr-ferrites, related to the iron oxides, produced from three different process in steel plants, have been investigated. The powder f.characteristics of iron oxides are much affected on the magnetic properties of calcined Sr-ferrite Powders. It was possible to improve the magnetic property of calcined Sr-ferrites with the iron oxide powders of small size and narrow size distribution. The maximum magnetic properties of calcined Sr-ferrites, showing 69 emu/g of saturation magnetization and 4020 Oe of intrinsic coercivity, are achieved at the following conditions; the iron oxides from the chemirite process(EP), mole ratio of 5.8, and calcination condition of 120$0^{\circ}C$/1hr.

기본 조성식 M $n_{1-x}$/F $e_{2+x}$/ $O_4$(이하 Mg계), M $n_{1-x}$/F $e_{2+x}$/ $O_4$(이하 Mg계)의 식에서 x를 0.0,0.025,0.1,0.2로 변화시키고, 하소온도 80$0^{\circ}C$, 소결은도를 l10$0^{\circ}C$~12$50^{\circ}C$로 $50^{\circ}C$간격으로 변화 시켰을 때와 Mn계와 Mg계를 1:1로 흔합하였을 때, F $e_2$ $O_3$의 과잉 양이 증가할수록 비저항은 감소하였고, 저항온도계수 $\alpha$는 밀도와 비례하는 관계를 나타내었으며, B정수는 4600(K)에서 10500(K)의 범위를 나타내었다. 본 조성의 실험으로써 Mn-Ni-Co계 서미스터의 대체가 가능함을 확인할 수 있었다.있었다.

The absorption coefficient of contrast media was meassured region of diagnostic radiology. Relative values of absorption coefficient was fecund the largest peak in the range of 60 ∼ 70kVp for sodium sulfate and 60kVp for iodine. Increasing the thickness of contrast media and patient the values of absorption coefficient was rising.

In this paper, we inveatigate frequency dependance of inductance effects of FeCoB amorphous magnetic films. First, amorphous magnetic film having near zero magnetostriction is the basic composition of (Fe$_{1-x}$ / $Co_{x}$)$_{79}$Si$_2$B$_{19}$ with x=0.94, 0.95 and in order to decrease magnetio . anisotropy, the film was annealed in 28$0^{\circ}C$/30min, 40$0^{\circ}C$/30min, 40$0^{\circ}C$/1hr with near crystallization temperature under non-magnetic field. As result of investigation, in case of x=7.95 than x=0.94, we could have obtained high values, which inductance ratios in the low frequency was 488%. And Quality factor Q was under 0.7 in all sample, in case of annealed in 28$0^{\circ}C$/30min, we could have obtained highest value, which x=0.9fl is about 0.62 in 400[kHz], and in case of x=0.95 was about 0.35 in 1[MHz].z].].

It was investigated that space charge characteristics of EPDX/LPE laminates as a function of interfacial condition. There were no effects in charge accumulation characteristics at EPDM/XLPE laminate samples which were pasted with silicone oil and silicone grease. But when the crosslinking coagent (TMPTA) was pasted in laminate samples, there was no space charge in interface of EPDE/XLPE laminate and no effects in the laminate sample pasted with silicone grease dissolved crosslinking coagent. In the coupling agent pasted EPDhyXLPE laminate sample, space charge was accunlulated in XLPE side caused by coupling agent.

We synthesized polyaniline films electrochemically under constant current conditions, which exhibited electric conductivity as high as 100 S/cm. By charge and discharge cycling of polyaniline films, we obtained specific discharge capacity as high as 195 mAH/g using HSO$_4$- doped polyaniline. For the polyaniline synthesized using H$_2$SO$_4$ and HClO$_4$ composite electrolyte. we also obtained specific discharge capacity as high as 134 mAHg which rivals inorganic electro- active materials.

High-power piezoelectric materials are being developed for applications such as actuators and ultrasonic motors. In this paper, ferroelectric property of iron-doped 0.57 (Sc$_{1}$2//Nb$_{1}$2/)O$_3$-0.43 PbTiO$_3$. which is the morphotropic phase boundary composition for the PSN-PT system, was investigated. The maximum dielectric constant ( $\varepsilon$$_{33}$/$\varepsilon$$_{0}$ = 2551) and the minimum dielectric loss(tan $\delta$ = 0.51 %) at room temperature were obtained at 01. wt% and 0.3 wt% of iron additions. With additions of the Fe$_2$O$_3$ the electromechanical coupling factor of radial mode k$_{p}$ and the piezoelectric coefficient d$_{33}$ were slightly decreased, on the other hand the mechanical quality factor was increased significantly. The highest mechanical quality factor (Qm= 297) was obtained at 0.3 wt% Fe$_2$O$_3$, which is 4.4 times larger than that of pure 0.57 PSN-0.43PT ceramics. The temperature dependence of the dielectric constant and dielectic loss was observed between 2$0^{\circ}C$ and 35$0^{\circ}C$ .X> .X> .

This paper presents a patch antenna design method using microwave dielectric ceramic substrate. Before manufactirung the GPS(Global Positioning System)antenna such contents as input impedence resonent frequency and quality factor and efficiency are surveyed theolitically for design and parameters for manufacturing the antenna are found.

In this paper, the electrical and dielectrical properties were investigated in Pb(Zr,Ti)O$_3$-Pb(Mn,Nb)O$_3$ ceramics which are manufactured with the substitution of Ba in site Pb. In older to increase the del and Kp , Ba was substitued to site Pb from 0 to 0.1 by 0.02 mol%. As the Ba substitution is increased, dielectric constant is increased and electricmachanical coupling factor showed the maximum value at Ba 0.06mol% and the mechanical qualify factor is decreased and the tetragonality and the grain size are decreased as the Ba substitution.

Electroluminescent(EL) dcvice based on organic thin layers have attracted lots of interests because of thier possible application as large-area light-emitting displays. It was known that MEH-PPV and 1, 1, 4, 4, -Tetraphenyl-1, 3-butadiene(TPB) has red and blue emission peak at 580nm and 480nm, respectively. In this study, MEH-PPV films and TPB films were prepared by spin coating and vacuum deposition method, respectively. Films of MEH-PPV and TPB double layer were also prepared by the same method. Photoluminescent(PL) characteristics of these single and doubler layers were investigated, where a cell structure of glass substrate/ITO/MEH-PPV and/or TPB/Al was employed. It was found that the photoluminescent efficiency of TPB film was higher than that of MEH-PPV film with a single layer and also with a double structure. These films have also different I-V characteristics.

The electron swarm parameters and Energy distribution function have been calculated for electrons motion through CH$_4$ pure gas under the action of uniform electric field for 0.1$\leq$E/N(Td)$\leq$300, at the 300( $^{\circ}$K), using MCS method and Boltzmann transport equation. And then the resulting values of electron drift velocity were compared to experimental data and adjustment made in assumed cross sections until good agreement was obtained. The electron drift velocity is very useful in the fields of study relating to the conductive and dielectric phenomena of gas medium. The electron energy distribution in gas discharge are generally nonmaxwellian , and must be calculated by a numerical solution of the Boltzmann equation which takes in the elastic and inelastic collisions. To analyze the physical phenomena and properties (or electron swarm motion in a gas under the influence of an electric field, the energy distribution function of electrons and the theoretical deriveration of the electron drift velocity are calculated by the Backward Prolongation with respect to the Boltzmann transport equation as a parameter of E/N(Td).

The III-V nitride semiconductor InN thin films which have the direct bandgap in visible light wavelength region have been deposited on Si(100) substrates and AIN/Si(100) substrates by rf reactive sputtering. InN thin films have been investigated on the structural, and electrical properties according to the sputtering parameters such as total pressure, rf power, and substrate temperature. It is found that optimal conditions required for fabricating InN thin films with high crystal Quality, low carrier concentration, high Hall mobility are total pressure 5mTorr, rf power 60W, substrate temperature 6$0^{\circ}C$ . InN thin films deposited on the AIN(60min.)/Si(100) substrates arid AIN(120min.)/Si(100) substrates showed remarkably high crystal quality and electrical properties. It is known that AIN buffer layer is to decrease free energy at interface between InN film and Si substrate, and then promoting lateral growth of InN films.

A new piezoelectreic transformer is proposed as a key device for high power transimssion. The piezoelectric transformer made of lead titanate solid solution creamic is operated with a thickness extensional vibration mode. This transformer can operate at high frequency aver several megahertz with about 90% high efficiency.

Superconducting thick films were fabricated with various paticle sizes on Allumina substrates by MPMG method. The sample of about 63${\mu}{\textrm}{m}$ in this experimented the size of particles was the best for uniformity and the number of Y211. In this experiment It is observed that powder size is very important to fabricate the superior thick finns.

The influence of slow cooling and annealing time in $O_2$ during melting and growth step in MPMG process on J$_{c}$ was investigated. Through the measurement of J$_{c}$ SEM and XRD, it can be observed that the critical characteristics were related with the slow cooling time and annealing time in 02 for melting and growth step of MPMG process. The distribution of critical current density with slow cooling time was the porabolic form and the value of J. was the highest at the 40 hour slow cooling time. And also, the value of J$_{c}$, along the annealing time in $O_2$ in the case of the slow cooling time 40 hour was inclined to increase with annealing time. Consequently, it can be suggested that proper slow cooling titre and annealing time along slow cooling in MPMG process be important to improve the critical characteristics.stics.

(S $r_{0.85}$/C $a_{0.15}$)Ti $O_3$(SCT) thin films at various deposition temperature and rf power were grown by rf magnetron sputtering method on optimized Pt-based electrodes (Pt/TiN/ $SiO_2$/Si). The crystallinity of the films increases with increasing deposition temperature. SCT thin film is depend on the surface morphology and crystallinity of Pt films for bottom electrode. Dielectric constant of (S $r_{0.85}$C $a_{0.15}$)Ti $O_3$ thin films deposited on Si wafer substrate are larger with the increase of deposition temperature and gain size.in size.

A hydride vapor phase epitaxy (HVPE) method was performed to prepare the thick-fi lm GaN on AIN/Si substrates. We obtained substrate-free GaN. The foul t-width at half maximum of double crystal X-ray rocking curve from 350 ${\mu}{\textrm}{m}$ thick substrate-free GaN was ~1000 arcsec. The photoluminescence spectrum (at 20 K) shows the narrow bound exiton (I$_2$) line and wealth donor-acceptor pair recombination however. there was not observed deep donor-accepter pair recombination indicate the substrate-free GaN crystal prepared in this study are of high purity and high crystalline quality.

We investigated the generation of pretilt angle for nematic liquid crystal (NLC) in a cell with slanted non-polarized ultraviolet (UV) light irradiation on mixtured polyimide (PI) surfaces. It was found that the monodomain alignment of NLC is obtained in a cell with an angle of incidence of 75∼85 degrees on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect due to photo-depolymerization of polymer on Pl surfaces. We successfully observed that the pretilt angle of NLC is generated above 5 degree with an angle of incidence of 75∼85 degree. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecules and the Polymer surfaces.

We investigated grain boundary effect for terrestrial applications of solar cell\ulcorner with low cost, large area, and high efficiency. Grain boundaries are known as potential barriers and recombination centers for the photo-generated charge carriers, which make it difficult to achieve a high efficiency cell. To reduce these effects of grain boundaries, we investigated various influencing factors such as thermal treatments, various grid patterns, selective wet etchings for grain boundaries, buried contact metallizations along grain boundaries, and use of metallic thin films. From the various grid patterns we learned that the series resistance of solar cell reduced open circuit voltage and consequently decreased the cell efficiency. This paper describes the effect of various grid patterns and the employment of metallic thin films for a top electrode.

In the fields of the optics, precise machine, semiconductors, the micro-positioning actuators are required for the control of position in the submicron range. PNN-P2N-PZT ceramics were fabricated with various mole ratio of the PZT[Pb(Zr$_{1}$2//Ti$_{1}$2)O$_3$]. PNN (Pb(Ni$_{1}$3/Nb$_{2}$3/)O$_3$]and PZN[Pb(Zn$_{1}$3//Nb/sbu 2/3/)O$_3$] powders prepared by double calcination and PZT powders prepared by molten- salt synthesis method. The relative permittivity of specimen with PZT 0.3 mole ratio was shown 5,320 and appeared the relaxor ferroelectric feature. The maximum Piezoelectric coefficient d$_{31}$ to be used for evaluation the displacement of piezoceramics in PNN-PZN-PZT ceramics was 324$\times$10$^{-12}$ (C/V) at the vicinity of morphotropic phase boundary and was larger than that of solid PZT ceramics(120$\times$10$^{-12}$ C/V).

ZnO and A1$_2$O$_3$ powders were mixed in 1 : 1 mole ratio and ball-milled with ethanol for 3 h. After the pressing process, the mixtures were sintered at $700^{\circ}C$~130$0^{\circ}C$ for 5 h in air to form ZnA1$_2$O$_4$. Structural properties were analyzed by X-ray diffraction patterns ; optical properties by absorption spectra with UV-VIS-H[R Spectrophotometer ; microstructural properties by SEM ; photoluminescent properties by using PL Measuring System. In result, ZnAl$_2$O$_4$ phosphor is crystallized at 110$0^{\circ}C$ and optical bandgap is calculated at 4.65 eV. PL spectrums were shifted to longer wavelengths with increasing temperature and was appeared around 780nm at 130$0^{\circ}C$ . Additionally, the peak intensity was veil strong at 80$0^{\circ}C$ and was declined with increasing temperature.

(Ba,Sr)TiO$_3$ thin film capacitors were prepared on SiO$_3$/Si(100)wafer by RF sputtering technique. The structural and crystallographic properties were studied with deposition conditions and annealing temperatures. Microstructural properties of (Ba,Sr)TiO$_3$ thin films were investigated by the SEM, XRD. The thickness and grain size were studied for the varying of RF power and temperature.

In this study we investigated the acting characteristics of Polymers for electrical insulation by UV radiation and salt water spray treatment. We used the Polymers such as EPDM, SR. PTFE. EVA. We measured contact angle and surface resistance to know the aging characteristic of Polymer surface. And we use SEM to observe the change of the surface shape. Dry flashover voltage test impulse voltage test were carried for the polymer insulator(EVA) . Through this experiment and the analysis we could know the polymers have a good resistance to weathering conditions like as salt spray UV irradiation and mix of them. And we can compare the aging characteristics between Polymers. As a result, we could know that the surface characteristics of PTFE is better than the other. And the degree, electrical characteristics is affected by change of surface shape is not big.

The main fault in this interface is that power cable insulating materials are mainly composed of a double layered structure, XLPE/FPDM laminates in cable joint. In this parer, we instituted the interface of XLPE/EPDM laminates and then investigated the breakdown and conduction characteristics as a function of heat treatment time. The results showed that conduction current was influenced by volatile crosslinking by-products which remained inside the insulating material during the production of XLPE and EPDM, especially during heat treatment process. And conduction current of XLPE/Oil 12500cSt/EPDM was more stable than XLPE/Grease/EPDM from the long heat treatment time. AC breakdown strength of silicone oil itself from the heat treatment was changed during the 4∼12 hour heat treatment time.

In this paper, we describe about the field test of polymeric long rod insulator for rail way. For the test, insulators were mounted at the feeder line system at Kuro base station and were exposed to environmental, electric, and mechanical stress. During the test service, the leakage current was been monitoring and stored the data by the leakage current measuring system that was specially constructed. After about 6 months, diagnostic tests for evaluation of the installed insulators were conducted. The test results developed that the developed polymeric insulator is valid to use for rail way.

An investigation has been made of the various plasma chemistry reactions that occur in the corona discharge of an electrostatic precipitator operating in a typical flue gas. As the results of investigation, sulphur dioxide is removed principally by reactions with OH radicals to produce sulphuric acid, while nitrogen oxides are removed principally by reduction via the N radical to molecular nitrogen. If electrostatic precipitator\ulcorner used for flue gases are operated with positive voltages instead of negative dc voltages, there are significant reductions in the emission of the undesirable gases SO$_2$, NO, and NO$_2$. Thus, in this paper we design the bidirectional pulse generator for removal of flue gas, where the pulse width is more than 50[nsec] and the maximum output voltage is more than 100[kVl.

It is necessary to know the accurate field distribution around the high power apparatus, in designing it. To calculate the field around electrodes, we use the Charge Simulation Method(CSM) among several numerical methods and develop the new \"Field Analysis System\", by which we can draw the shape of electrodes, save the drawing in ascii code and apply CSM on the data. In the Field Analysis System, we try several rules for arrangement of simulation charge on CSM and consider their accuracy. At firs we simulate the case with simple electrode geometry and consider the adequacy of the rules. With tole field Analysis System applied the rules, we simulate the main electrode of load switchgear. As a result of the simulation, equipotential line, flux line and field strength on male electrode are drawn.

Co single layer and Co/Ti used to form a CoSi$_2$ contact. We fabricated the n+/p diodes with this CoSi$_2$ contact as diffusion source of As. The diodes wish CoSi$_2$ formed by Co/ri bilayer had more Bo7d electrical characteristics than CoSi$_2$ formed by Co single layer. This shows that the flatness of interface which is a parameters to affect the diodes\` electrical characteristics. And the electrical characteristics of diodes are more good when the second thermal activation processing temperature was low as much as 50$0^{\circ}C$ than the temperature high over than 80$0^{\circ}C$, it was thought as that the silicide was degradated at high temperature.

Diamond thin films were deposited on Si wafer from a mixture of CE$_4$ and H$_2$ by RF Plasma CVD. The films were de77sited under the following conditions : discharge power of 500w, H$_2$ flow rate of 30sccm, chanter pressure of 20∼50Torr, and CH$_4$ concentration of 0.5∼2%. The deposition time was 30∼40 hours because of low growth rate. The deposited films were characterized by Scanning Electron Microscopy and X-ray Diffraction method.

Generally, Piezoelectric ceramics based lead-zirconate-titanate(PZT) system are well known to use in high power devices. In this pacer. Pb(Mn$\sub$1/3//Sb$\sub$2/3/)O$_3$(PMS) ceramics which have been shown to be adaptable for a high power usage is introduced. The stability of piezoelectric properties in PZ-PT-PMS solid solution system such as piezoelectric constants. electromechanical coupling coefficient and mechanical quality factor is discussed by the addition effect of CeO$_2$ as a additive. The CeO$_2$ ratio ranges from 0 to 2 wt%. The resonant and anti-resonant frequencies. mechanical quality factor, and force factor are also measured as a function of vibration velocity

In this paper, we investigated the effects of gap length and tip radius influenced in breakdown of mineral based insulation oil Electrode system was needle-plane geometry It is to model conductive extrusions in oil filled electrical power apparatus. The tip radius of needle electrode was 5, 10, 20 and 25${\mu}{\textrm}{m}$, respectively. We measured breakdown voltage for each of tip radius with increasing electrode gap, 2mm to 12mm. It was calculated electrical breakdown strength at tip using Mason\`s equation from breakdown voltage As gap lenght increased. breakdown strength increased linearly. But, as tip radius of needle increased, breakdown strength decreased exponentially. It can be explained by tole phenomenon that electron is easily injected, as tip radius increases, and effective work function decreases. When appling DC voltage. breakdown 7tr7ilgtll was higher wheal polarity of needle was negative than positive. It is because of the space charge effect ill accordance with the influence of liquid motion.

The sealing integrity is related to the safe operation of arrester the prime failure reason of porcelain housed arresters is moisture ingress. To be a meaningful tests a polymer arrester sealing test must be a realistic acceleration of field service. We think the test should be an accelerating course of actual temperatures, the enduring property to mechanical load and temperatures should be considered together. A union test method consisting of the thermal mechanical test and thermal cycling test is proposed to test the sealing integrity of polymeric arresters, which uses dielectric loss, leakage current 1mA DC voltage and partial discharge as the diagnostic techniques, and the test results were presented. The comparison states that the TMTCUT method is suitable fur the test of sealing integrity of polymeric arresters. .

Various polymeric electrolytes were prepared from PEG, PEO and PMMA with LiClO$_4$ to develop lithium conductive electrolytes for smart windows. The complementary electrochromic devices were fabricated with these electrolytes involving cathodically coloring WO$_3$ and anodically coloring V$_2$O$\sub$5/ thin films. The performance of electrochromic device with PMMA/LiCLO$_4$ electrolyte was found to be excellent

Hot carrier effects as a function of bias stress time and bias stress conditions were syste-matica1ly investigated in p-channel po1y-Si TFT's fabricated on the quartz substrate. The device degradation was observed for the negative bias stress. After positive bias stressing, Improvement of electrical characteristic except for subthreshold slope was observed. It was found that these results were related to the hot carrier injection into the gate oxide and interface states at the poly-Si/SiO$_2$interface rather than defects states generation under bias stress.

The numerical model that can describe the ignition of the pseudospark discharge using hybrid fluid-particle method has been developed. The evolution process of the discharge has been divided into four phases along the potential distribution. After the plasma enters in the hollow cathode, the confining effect which is one of hollow cathode properties occurs and the electron current on anode rises rapidly. As the plasma expands successively, the sheath contracts and as the electric field in the sheath increases, the field-enhanced thermionic emission(Schottky emission) occurs. From numerical results, the physical mechanism that causes the rapid current rise in the ignition of the pseudospark discharge could be identified.

We investigated effectness of sort and volume of conductive agent to charge/discharge capacity of LiMn$_2$O$_4$. LiMn$_2$O$_4$is prepared by reacting stoichiometric mixture of LiOH . $H_2O$ and MnO$_2$(mole ratio 1 : 2) and heating at 80$0^{\circ}C$ for 24h, 36h, 48h, 60h and 72h. All LiMn$_2$O$_4$cathode active materials show spinel structure. Cathode active materials calcined at 80$0^{\circ}C$ for 36h, charge/discharge characteristics and cycle stability have remarkable advantages. Used that super-s-black and 20wt% as conductive agent in LiMn$_2$O$_4$, it is excellent than property of cathode used Acetylene black or mixture of Super-s-black and acetylene black at charge/discharge capacity and cycle stability. Also, specific efficiency of cathode is excellent as over 98% and that of first cycle is excellent as 92%.

The propose of this study is research and improvement of LiNiO$_2$as cathode material for Lithium secondary batteries. LiNiO$_2$is prepared by heating LiOH . $H_2O$ and Ni(OH)$_2$(mole ratio 1 : 1) on various heat condition. In the result of XRD mesurement, all LiNiO$_2$prepared at this study showed hexagonal structure. In Cyclic Voltammetry, LiNiO$_2$is not conspicous about oxidation peak but oxidation curve change steeply over 3.8V and reduction peak discover at 3.6V. In discharge capacities, specific capacity is higher $O_2$than air when preliminary heated and 75$0^{\circ}C$ than $700^{\circ}C$, 80$0^{\circ}C$ when heated. Therefore, when preliminary heat at $650^{\circ}C$ $O_2$and heat at 75$0^{\circ}C$ carried out, discharge property is the best.

We have obtained disordered carbon by pyrolyzing PPP in a nitrogen atmosphere for 8 hour at 700$^{\circ}C$. AC impedance property was measured with the PPP-based carbon/EC-DEC/Li cell. The impedance spectra of the cell were measured during the 1st discharge proceed. As the result of measurement the cell resistance decreased in intial discharge, but increase in final discharge.

It was studied that the effect of the mixing materials and the mole ratios on electrochemical properties of LiMn$_2$O$_4$LiMn$_2$O$_4$is prepared by reacting stoichiometric mixture of LiOH.$H_2O$ and MnO$_2$(EMD or CMD) and heating at 80$0^{\circ}C$ for 36h. We obtained properties of crystal structure through X-ray diffraction. LiMn$_2$O was reversible at 4.5V~3.0V and displayed two reduction and oxidation. Optimum synthesis results were obtained by reacting with LiOH.$H_2O$ and MnO$_2$(EMD) at mole ratio 1:2.

In this paper, volume resistivity is studied so that the electrical properties for transformer oil due to the stirring temperature of BTA is investigated. A measurement of volume resistivity using the VMG-1000 highmegohm meter is recorded after 10 minutes when the each voltage, and DC 100[V], 250[V], 500[V] and 1000[V] is applied, according to the step voltage appliaction method. A coaxial cylindrical liquid electrode to measure volume resistivity of specimen is used, and its geometric capacitance is 16[pF].

A study has been carried out electrical conduction properties of synthetic fluids No. 2 of KS class VII used for insulating and cooling the power device. BTA(Benzotrizole) as the streaming electrification suppressant additive is added to the oil, and the change of physical and electrical properties due to different BTA concentration is investgated. From the result of FTIR spectrum, it is confirmed that the absorpption peak in wavenumber 3400-3450[cm$\sub$-1/] is smaller and disappered by adding BTA to the oil. It is considered that the effective content of BTA is about 10[ppm] from the result of electrical conduction experiment.

This paper describes the thermally stimulated current(TSC) measurements arachidic acid(AA) and polyamic acid alkylamine salts(PAAS) LB film, which is a precursor of polyimide(PI). The measurements were performed from room temperature to about 250$^{\circ}C$ and the temperature was increased at a rate of 0.02 $^{\circ}C$/s linearly[4]. It shows that peaks of TSC are observed at about 80$^{\circ}C$ in the arachidic acid and about 80$^{\circ}C$, 160$^{\circ}C$ in the PAAS LB films. The DSC and TGA of PAAS, arachidic acid are measure. Monolayer phases on the water subphase such as Langmuir(L) films and the phase transitions from gas phase to solid phase via liquid phase are observed using Brewster angle microscopy(BAM). BAM is also used to observe the Langemuir-Blodgett(LB) films.

Treeing due to partial discharge(PD) is one of the main causes of breakdown of the insulating materials and reduction of tile insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation has become important. From this viewpoint, our studies diagnose insulation degradation using the method of computer sensing system, which has the advantages of PD and acoustic emission(AE) sensing system. To use advantages of these two methods can be used effectively to search for treeing location and PD in some materials. In analysis method of degradation. using statically operator such as the center of gravity (G). the gradient of the discharge distribution(C), we have analyzed far tole prediction of life which we can be obtained the time, occurred of many pulse of small discharge amplitude.

The Maxwell displacement current was investigated in the connection with stwiching characteristics by photoisomerization of monolayers. The displacement current was generated due to the trans-to-cis photoisomerization by irradiation with ultraviolet light( λ$_1$1=360nm). whereas the displacement current was generated in the opposite direction due to the sis-to-trans photoisomerization by irradiation with visible light( λ$_1$=450nm). The reversible displacement current generation was found to be sustained by alternative irradiation with UV light and visible light.

The Ce-Cr(-Ta) film are one of the most suitable candidates for perpendicular magnetic media. the control of the preparation conditions, such as Ar gas pressure P$\_$Ar/ substrates temperature T$\_$s/, films thickness $\delta$, deposition speed R$\_$d/, is considered to be important to attain ultra high density recording far perpendicular magnetic recording media. In this study, the Co-Cr thin films and Co-Cr-Ta thin films were deposited on the glass side substrates by using Facing Targets Sputtering apparatus(FTS). Crystallographic characteristics and magnetic characteristics were evaluated by X-ray diffractometry(XRD), Vibrating Sample Magnetometer(VSM) respectively.

The effects of aromatic curing agent of MDA contents and post curing conditions on dielectric deterioration characteristics of DGEBA/MDA/SN system were investigated. The dielectric properties were measured by using needle-plane electrode geometry under the commercial AC high electric field application. As the curing agent content increased, the dielectric breakdown strength increased and then decreased slightly. All the trees initiated from the tip of needle electrode and the shape of the tree in this system was a dendrite type.

The paper reports on a study of the influence of the size of the particles of alumina trihydrate(ATH) filler on the surface aging characteristics of ehylene propylene diene terpolymer(EPDM). A fixed 100pph concentration of the filler of ATH was used (or all particle sizes from 0.7 to 20$\mu\textrm{m}$, It is show that hysteresis of contact angle and leakage current increase with increasing particle size, whereas tracking resistance decrease with increasing particle size.

In this study, Efficiency estimation of ultrasonic sensor fabricated with porous piezoelectric resonator by experiment of 3-D underwater object recognition are presented. The sensor was satisfied with requirement of ultrasonic sensor. The recognition rates for the fixed objects and the translation-rotation objects are 95.3 and 92.7[%], respectively using porous piezoelectric ultrasonic sensor and SOFM neural network. According to the experimental results, It is believed that the self-made ultrasonic sensor can be applied as underwater ultrasonic sensor.

TFT2DS was developed to provide the usability as an analytic and design tool. The static characteristics of a-Si TFTs demonstrated a good agreement between simulated and measured data. This paper shows that WDS can optimize the physical parameters of a-Si through sensitivity simulations and compute the static characteristics of a-Si TFTs.

Organic semiconductors such as conjugated polymers and oligomers have been studied many research groups. The band structures of conjugated polymers and oligomers are similar to those of conventional inorganic semiconductors Thin films based on these materials show a promising potential for Field Effect Transistors(FETs) and Light Emitting Diodes(LED) because fabrication processes are simple and cheaper for large electronic devices and flexible devices are also possible.

The electrical and physical charateristics of aluminum oxide and Pt thin films on it, deposited by reactive sputtering and DC magnetron sputtering, respectively, were analysed with increasing annealing temperature(400~80$0^{\circ}C$) by four point probe, SEM and XRD. Under $600^{\circ}C$ of annealing temperature, aluminum oxide had the properties of improving Pt adhesion to SiO$_2$and insulation without chemical reaction to Pt thin films and the resistivity of Pt thin finns was improved. But these properties of aluminum oxide and Pt thin finns on it were degraded over $700^{\circ}C$ of annealing temperature because aluminum oxide was changed into metal aluminum and then reacted to Pt thin films deposited on it. The thermal characteristics of Pt micro heater were analysed with Pt-RTD integrated on the same substrate. In the analysis of properties of Pt micro heater. active area was smaller size, Pt micro heater had better thermal characteristics. Temperature of Pt micro heater fabricated on membrane was up to 34$0^{\circ}C$ with 1.2watts of the heating power due to reduction of the external thermal loss.

Platinum-Cobalt alloy thin films were deposited on A1$_2$O$_3$substrate by magnetron cosputtering for RTD temperature sensors with wide temperature ranges. We made Pt-Co alloy resistance patterns on the A1$_2$O$_3$substrate by lift-off method and fabricated Pt-Co alley RTD temperature sensors by using Pt-wire, Pt-paste. We investigated the physical and electrical characteristics of theme films under various conditions, input power, working vacuum, annealing temperature and time, and also after annealing these films. The resistivity and sheet resistivity of these films were decreased with increasing the annealing temperature. At input power of Pt : 4.4 W/cm$^2$, Co : 6.91 W/cm$^2$, working vacuum of 10 mTorr and annealing conditions of 800$^{\circ}C$ and 60 min, the resistivity and sheet resistivity of Pt-Co thin films was 15${\mu}$$\Omega$$.$cm and 0.5$\Omega$/ , respectively, and the TCR value of Pt-Co alloy thin films with thickness of 3000${\AA}$ was 3740ppm/$^{\circ}C$ in the temperature range of 25∼600$^{\circ}C$. These results indicate that Pt-Co alloy thin films hove potentiality for the RTD with wide temperature ranges.

The optical properties of WO$_3$thin films deposited by RF magnetron reactive sputtering were studied. The substrate was an ITO(indium-tin-oxide) glass(100$\Omega$/ ). The optical properties are examined by different deposition conditions. RF power, substrate temperature, $O_2$concentraction. Ar flow rate, working pressure and thickness are 40~60W, 25~30$0^{\circ}C$, 10%, 54~72sccm, 5~20m7orr and 1200~2400$\AA$, respectively. All these films were colorless, light yellow and found to be amorphous in structure by X-ray diffraction analysis. When RF power, substrate temperature, $O_2$concentraction, Ar flow rate, working pressure and thickness are 40W, $25^{\circ}C$, 10%, 72sccm, 20mTorr and 2400$\AA$, respectively the values of transmittance of the WO$_3$thin films in visible region are about 80%.

This paper presents the basic characteristics of Cr thin-film, which were deposited on glass by DC magnetron sputtering. The optimized deposition condition of Cr thin-film strain gauges were input power 7w/cm$^2$and the Ar working pressure was 9mtorr. GF(Gauge Factor), TCR(Temperature Coefficient of Resistance) and TCS(Temperature Coefficient of Sensitivity) of Cr thin-film strain gauges were 5.86, 400 ppm/$^{\circ}C$ and 0 ppm/$^{\circ}C$, respectively.

In order to investigate CO sensing property of a SnO$_2$-WO$_3$composite ceramic. we prepared pure SnO$_2$and WO$_3$added SnO$_2$compostie ceramics. Using XRD and SEM, a phase analysis and microstructure were investigated. The resistances as a function of gas atmosphere were measured by High Voltage Measure/source Unit. The measured 1000ppm CO gas sensitivity of SnO$_2$-WO$_3$composite ceramics were smaller than that of pure SnO$_2$.

A new magnetic field measuring system with induced coil is reported. This system consists of air-cared coil that is forced by the ultrasonic transducer. Induction voltage of coil is proportional to the DC magnetic field and the driving frequency of ultrasonic transducer by the principle of Faraday's law. The experimental measuring system is setup, and the possibility of a new magnetic field sensors is confirmed.

The Effects of different melting temperature and holding time in the melting temperature on J$\sub$c/ of YBa$_2$Cu$_3$O$\sub$x/ based superconducting bulk using MPMG process were investigated. the value of critical current density was the largest at l120$^{\circ}C$, the melting temperature which is appointed to the mid point of (Y$_2$BaCuO$\sub$5/ + Liquid)region. With the melting temperature in which the value of J$\sub$c/ is the largest, J$\sub$c/ was again measured to see whether the holding time at this proper melting temperature has the effect on the critical characteristics. From the result above it was concluded that the melting temperature and holding time were important to improve the J$\sub$c/ and the formation of the Y$_2$BaCuO$\sub$5/. In this paper, the melting temperature obtained was l120$^{\circ}C$ and propel holding time could be obtained as 20 minute and the more holding time was not effective in the J$\sub$c/ improvement as well as the formation of Y$_2$BaCuO$\sub$5/.

The method of estimating life time of epoxy composites which be widely used for transformers has been studied in this paper. The breakdown properties of specimens are observed by appling high AC voltage at the room temperature from a series of the experiments. Afterwards, the breakdown time was determined under the constant voltage below the lowest breakdown voltage. Also, V-t properties were found out using weibull distribution widely used in the applications of discrete data for estimating life time of epoxy composites and life exponent n was gained properly. when life exponent is gained is found out, the tong breakdown life time at used voltage can be estimated from breakdown experiments in short time using reverse law of n power.

We have investigated Pt and RuO$_2$as a bottom electrode for a device application of PZT thin film. The bottom electrodes were prepared by using an RF magnetron sputtering method. We studied some of the property influencing factors such as substrate temperature, gas flow rate, and RF power. An oxygen partial pressure from 0 to 50% was investigated. The results show that only Ru metal was grown without supp1ying any O$_2$gas. Both Ru and RuO$_2$phases were formed for O$_2$partial pressure between 10∼40%. A Pure RuO$_2$ phase was obtained with O$_2$partial pressure of 50%. A substrate temperature from room temperature to 400$^{\circ}C$ was investigated with XRD for the film crystallinity examination. The substrate temperature influenced the surface morphology and the resistivity of Pt and RuO$_2$as well as the film crystal structure. From the various considerations, we recommend the substrate temperature of 300$^{\circ}C$ for the bottom electrode growth. Because PZT film growth on top of bottom electrode requires a temperature process higher than 500$^{\circ}C$, bottom electrode properties were investigated as a function of post anneal temperature. As post anneal temperature was increased, the resistivity of Pt and RuO$_2$was decreased. However, almost no change was observed in resistivity for an anneal temperature higher than 700$^{\circ}C$. From the studies on resistivity and surface morphology, we recommend a post anneal temperature less than 600$^{\circ}C$.

Wire Ion Plasma Source (WIPS) is a plasma device which has a thin wire anode, a coaxially-set cylindrical cathode and electrodes located in both ends of the cylinder. The potential between the anode and cathode changes logarithmically by this electrode configuration. This electrode configuration enables high-density plasma to produce even at a low anode voltage. Since the electrode configuration is axially symmetric and long. plasma with axially uniform number density can be produced. Using particle-in-cell(PIC) and Monte Carlo collision(MCC), we investigate the traiectory of electrons and the characteristics of D.C. discharge in Wire ton Plasma Source.

Diamond thin films were deposited on P-type(100) Si wafers using MPECVD. Prior to deposition, mechanical scretching was done to improve density of nucleation sites with diamond paste of 0.25${\mu}{\textrm}{m}$ size. Diamond films were deposited under the following conditions : methane concentration of 0.5~5%, oxygen concentration of 0~70%, process pressure of 70Torr, process temperature of 900~95$0^{\circ}C$, and deposition time 5hrs. The changes of the morphology and the growth rates of the deposits with the experimental conditions are expriend by Scanning Electron Microscopy. Raman Spectroscopy and X-ray Diffraction method.

In order to investigate the electrical characteristics due to the curing condition of silicone gel for Power Semiconductor, the V-I characteristics is studied. For experiment, We have made up several samples of different curing temperature and time such as 1[H],2[H] at 150[$^{\circ}C$], 160[$^{\circ}C$], 170[$^{\circ}C$]. As a result of the V-I characteristics, it is confirmed that the properties of specimen cured at 170[$^{\circ}C$], 2[H] is stable.

This paper describes the method of diagnosing the degradation by void defects of insulator inside in operation. Needle-shape void specimens, made from LDPE, were used to generate an electrical tree under ac voltage. The method uses a neural network system with input signal of AE patterns. AE pattern consists of the pulse count and average amplitude according to the phase angle. After the learning process was over, unknown emission patterns were put into the network. It was shown that the network discriminates the void deflects well. The effectiveness of the neural network system for partial discharge recognition was shown.

We hate examined the electrical properties of L-${\alpha}$-DLPC Langmuir(L) films by using a displacement current measuring technique with pressure stimulation. Displacement current was generated when the sample spread volume was about 280${\mu}\ell$, 360${\mu}\ell$ and compression velocity was about 30, 40, 50mm/min. Displacement current was generated in the range of gas state, gas/fluid state and fluid state in the course of monolayer compression. From the result, it is known that displacement current is generated in the range of high surface pressures as compression velocity become faster.

Glutaronitrile(GN) was introduced to diglycidyl ether of bisphenol A(DGEBA)/ 4,4'-methylene dianiline(MDA) system to improve toughness. Effects of GN contents on thermal decomposition of epoxy resin system were investigated. To study the characteristics of thermal decomposition, thermo-gravimetric analysis(TGA) and Kissinger equation were used. Thermal degradation temperatures were about 365$^{\circ}C$ regardless of GN contents. Activation energies of thermal decomposition in epoxy resin system were almost constant below 10 phr and decreased above 15 phr.

Electro Discharge Machining (EDM) is a so-call non-conventional machining technique. This paper presents the experimental results of an EDM technique for the fabircation of microholes on #7440 pyrex glans. With various applied voltages and at various concentration of KOH solution, the glass substrate have been microdrilled using the copper electrodes of which diameters are 250$\mu\textrm{m}$ to 450$\mu\textrm{m}$, respectively. The machined throughholes have been observed the top diameter, the bottom diameter, hollow width and hole diameter of the hole, and machining time hale been measured. The experimental results show that the machining time decreases as the concentration of KOH solution increases or the applied voltage increase. Also, The top diameter increases as the concentration of KOH solution decreases or the allied voltage increases. The bottom and hollow width decreases as the of KOH solution increases or the applied voltage decreases.

This paper presentes the characteristics of Si anisotropic etching and electrochemical etch-stop in aqueous TMAH/IPA/pyrazine solution. (100) Si etching rate of 0.747 $\mu\textrm{m}$/min which faster 86% than TMAH 25 wt.%/IPA 17 vol.% solution was obtained using best etching condition at TMAH 25 wt.%/IPA 17 vol.%/pyrazine 0.1 g and the etching rate of (100) Si was decreased with more additive quantity of pyrazine. I-V curve of p-type Si in TMAH/IPA/pyrazine was obtained. OCP(Open Circuit Potential) and PP(Passivation Potential) were -2 V and -0.9 V, respectively. Si diaphragms were obtained by electrochemical etch-stop in aqueous TMAH/IPA/pyrazine solution.

We prepared 0~20mo1% WO$_3$added ZnO composite ceramics in order to promote a CO gas sensitivity. Using SE,. we observed the microstructure of sample. The resistances of sample were measured by High Voltage Measure/source Unit in the temperature range of +5V~-5V. The measured 1000ppm CO sensitivities of pure ZnO were about 1~4.3, and the measured 1000ppm CO sensitivities of ZnO-WO$_3$composite ceramics were about 1~8.2. Therefore, the 1000ppm CO sensitivities of ZnO-WO$_3$composite ceramics were about 2 times larger than that of pure ZnO.

The microwave dielectric properties of CuO and CdO addition of BiNbO$_4$ceramics were investigated. As the content of CdO increased, sintered density and quality factor is decreased. With increase in sintering temperature, the dielectric constant and quality factor is increased. In case of specimen sintered at 96$0^{\circ}C$ with 0.03 wt% CuO and CdO, the microwave dielectric properties obtained were dielectric constant of 41.2, quality factor (Q$\times$f) of 6, 500, temperature coefficient of resonant frequency of ppm/$^{\circ}C$.

The phenomenon of water tree degradation of underground distribution power cables is taking place in polymeric insulation materials under the existence of water and application of electric stress, but water tree is not easy to observe, o water tree features in power cables are shown after cutting and dying with methyleneblue. In previous method, it is impossible to acquire continuous treeing data, and when the insulation material has been cut, the micro crack(water tree) has been damaged. In this paper, to overcome these deflects, the etching method is made use of making needle electrode about 170[${\mu}{\textrm}{m}$] diameter, and AgNO$_3$(silver nitrate) solution is used as liquid electrode to accelerate the growth of water trees. As a result of this study, water tree is observed in real-time with microscope. Electrical tree owing to water treeing is initiated at low electric field and grown with discontinuous. Namely, water tree is shown up a different characteristics of tree growth.

In this study, chlorine(Cl)-based gas chemistry is generally used to etching for AlCu films metallization. The corrosion phenomena of AlCu films were examined with XPS (X-ray photoelectron spectroscopy), SEM (Scanning electron microscopy), and TEM (Transmission electron microscopy). SF$\sub$6/ plasma treatment subsequent to the etch process prevents the corrosion effectively in the pressure of 300 mTorr. It is found that the chlorine atoms on the etched surface are not substituted for fluorine atoms during SF$\sub$6/ treatment, but a passivation layer on the surface by fluorine-related compounds would be formed. The passivation layer prevents the moisture penetration on the SF$\sub$6/ treated surface and suppresses the corrosion successfully.

We synthesized the polymer that can have function group and improvement of mechnical strength and then confirmed the possibility of molecular device made by LB method. In this paper, the $\pi$-A isotherm has been investigated as to the kinds and various concentrations of the metal ions complexed with imidazole group. The experimental results for the electrical properties of MIM fabricated has been obtained as following. There is no change in limiting area as to the kinds of the metal ions, also the shift of conductivity as to the metal ions couldn't be observed, which was 10$\^$-14/[S/cm]. There are some changes in limiting area as to the concentration of the metal ions, the conductivity shift was increased with the occupied molecular area.

Ti:LiNbO$_3$optical waveguides were fabricated as a function of Ti thickness and pigtailed with polarization maintaining fiber(PMF). The near field patterns and total insertion loss of these sample was showed and measured for optical wavelength 1550nm. The fiber-to-waveguide coupling loss was described also .

In order to compare with domestic underground distribution cables, the foreign cable which was manufactured in USA, 1982 and has been serviced in field for 13 years was characterized with several tests. Water trees, voids, and convolutions are not found in insulation. In hot oil test, insulation is very clean and there was no separation of insulation and conductor shield. The results of degree of crosslinking, FTIR, and DSC are also usual. Specially, the distribution of OIT is very good, which is different from that of domestic cables. The content of impurities is relatively small. This cables was manufactured with good state and no extraordinary degradation is found.

In AC PDP, electrodes are covered with dielectric layer and the discharge is formed on the surface of the dielectric layer. MgO protection layer on the dielectric layer in PDP prevents a dielectric layer from sputtering and lowers the firing voltage due to a large secondary electron emission yield( ${\gamma}$ ). Until now, the MgO protection layer is mainly prepared by E-beam evaporation. However, there are some problems that is easy pollution and change of its characteristics with time and delamination. Therefore, in this study, MgO protection layer is prepared on dielectric layer by reactive R.F. magnetron sputtering with MgO target. Discharge characteristics and secondary electron emission coefficients of PDP are studied as a parameter of preparation conditions. Discharge voltage characteristics of the prepared MgO layer can be stable and improved by the annealing process in vacuum chamber.

We investigated a electrical and CO gas sensing properties of pure ZnO and ZnO-ZrO$_2$ composite ceramics. We made 0∼20mo1% ZrO$_2$added ZnO composite ceramics and observed a microstructure of the broken side of the samples. The properties of the samples were studied with temperature, composition, arid a concentration of carbon monoxid. The measured 1000ppm CO sensitivities of pure ZnO were about 1∼1.42, and that of ZnO-ZrO$_2$were about 1∼10.6. In order words, the 1000ppm CO sensitivities of ZnO-ZrO$_2$composite ceramics were about 1∼2 times larger than that of pure ZnO with temperature. The measured 250ppm, 500ppm CO sensitivities of ZnO-ZrO$_2$composite ceramics were about ∼3.28. ∼5.04, respectively.

The properties of magnetic suppositories used in medicine has been tested with M ssbauer spectroscopy methods. The experiments were carried out on magnetic rectal suppositories containing parmadine and fine-dispersed ferrite powder BaO.nFe$_2$O$_3$as a magnetic filler. According to the data on the value of effective magnetic field on $^{57}$ Fe nuclei in ferrite magnetic sublattices, the stoichiometric n-number equals approximately 5.5; this vague corresponds to the composition range of optimal magnetic properties.

This paper presents green sheet Properties of multilayer chip filter for mobile communication. The role of solid loading content and lamination conditions in determining some of the green sheet properties are present. The optimun conditions were obtained solid loading 62:38, lamination temperature 7$0^{\circ}C$, lamination press 300~400 Kg/$\textrm{cm}^2$.

Temperature distribution measurements in the mockup apparatus of reactor vessel were performed to determine the effective thermal conductivity of Al powder porous media where stainless steel tubes were installed with different geometry. The temperature distributions at four separated sections with different arrangements of porous media have different slopes according to the geometrical configuration. From the measured temperature distribution, effective thermal conductivity have been derived using the least square fitting method.

The partial discharge has been blown as the chief breakdown of power equipments. The analysis and the recognition is much difficult because the partial discharge signal is very small and has complex aging pattern. Recently, insulation aging diagnosis based on pattern of phase(Ф), partial discharge magnitude(q), number(n) has been very important. Owing to depreciate the reappearance of aging progress at the electrical tree pattern and to be difficult to analyze visually, the study on partial discharge pattern is suggested to normalizing analysis method of partial discharge signals. This parer is purposed on prediction of life-time measurement of cv-cable, on decision of risk degree with normalization and real-time measurement of partial discharge signals for aging diagnosis of cv-cable. As normalizing the aging signals of electrical tree in cv-cable, it is able to confirm risk degree of insulation material with the distribution of Ф-q-n and recognize the process of aging pattern using neural network.

As device sizes are scaled to submicron dimensions, planarization technology becomes increasing1y important, both during device fabrication and during formation of multilevel interconnects and wiring. Chemical Mechanical Polishing (CMP) has emerged recently as a new processing technique for achieving a high degree of planarization for submicron VLSI applications. This paper is presented the results of CMP process window characterization studies for 0.35 micron process with 6 metal layers.

In this paper, the response characteristics for organic vapors has been studied using both itaconate copolymer and maleate copolymer, which have different hydrophilic group and same hydrophilic group. The conductivity of sensitive LB films was decreased in the range of 18 layers and maintained over 30 layers, which can describe the behaviors of urganic vapors such as penetration and surface absorption. It was thought that the organic vapors was penetrated into sensitive 13 films below 18 layer and the electrode was covered with sensitive LB film over 30 layers.

The oscillating properties of quartz Crystal Microbalance(QCM) were analyzed by electrical measurement. We tried to analyze the properties of quartz crystal coated with Langmuir-Bladgett(LB) films using the frequency and resistance at resonance in the electrical equivalent circuit. The resonant frequency was decreased linearly as to layers of LB films, however, there are some gap between theoretical values, Sauerbrey's equation and experimental values. The resistance was increase nonlinearly as to layers.

The effect of the surface state on the quantum efficiency of underlying GaAs/AlGaAs multi-quantum well(MQW) structures consisting of three GaAs quantum wells with different thickness, is studied by low temperature photoluminescence(PL). The structure was grown by molecular beam epitaxy(MBE) on (100) GaAs substrate. The thickness of three GaAs quantum wells was 3, 6 and 9 nm, respectively. The MQWs were placed apart from 50 nm AlGaAs edge-barriers including two inner-barriers with 15 nm in thickness. The samples used in this study were prepared with different growth temperatures. Particularly, the hydrogen passivation effect to the 9 nm quantum well located at near surface appeared much stronger than any others. Transition energy and optical gain related to the hydrogen passivation effects on the multi-quantum well structure was calculated by transfer matrix method.

Focused Ar ion laser beam can be utilized to fabricate microstructures on silicon substrate as well as other materials(e.g. such as ceramic). The laser using in this study is an argon ion laser with maximum power of 6 W, wavelength of 514 nm. This laser beam is focused by objectives with a high numerical aperture, a long working distance. We have achieved line width about 1 ${\mu}{\textrm}{m}$ with high scan speed. The resolution for Si machining is determined by the selectivity of the chemical reaction rather than the laser spot size. In this study, we have obtained the maximum etch rate of 434.7 ${\mu}{\textrm}{m}$/sec with high aspect ratio. The characteristics of etched groove was investigated by scanning electron microscope(SEM) and auger electron spectroscopy(AES). It is assumed that the technique using arson ion laser is applicab1e to fabricate microstructures.

The preparation of mach-zehnder inteferometric optical modulator and the properties of electrode and modulation bandwidth for high speed optical communications were described. The results of fabricated optical modulator was that optical 3-dB bandwidth 4.7GHz, driving voltage 6V and fiber-waveguide-fiber insertion loss 4.5dB for TM mode respectively.

This paper describes dielectric characteristics and discharge development mechanisms of SF$_{6}$ gas stressed by very fast transient overvoltages in inhomogeneous electric field. Predischarge phenomena of SF$_{6}$ gas in non-uniform fields are statistically investigated with positive and negative very fast trannsient overvoltages. It was confirmed that all of the predischarges of the positive and negative polarities develop in a regime of stepwise leader extension. i.e, the predischarge developments leading to breakdown against very fast transient overvoltages are similar to the non-oscillating impulse voltages.ges.

BSCCO thin film is fabricated cia both processes of co-deposition and layer-by-layer deposition at an ultralow growth rate using ion beam sputtering method. The adsorption of Bi atom and the appearance of Bi-2212 phase shows large differance between both processes. It is found that the resident time of Bi vapor species on the surface of the substrate strongly dominates the film composition and the formation of the structure.

Partial discharge characteristics of normal butyl acrylate grafted low density polyethylenes were investigated by an ultrasonic sensor made of ceramic piezoelectric material. It was found that the partial discharging activities in normal butyl acrylate grafted low density polyethylenes were considerably suppressed compared to those in plain low density polyethylene. It was found that acrylic acid grafted polyethylene was more effective than normal butyl acrylate grafted low density polyethylene.

We have made disperse diazo black D(DB-D) ultrathin films using Langmur-Blodgett(LB) and vacuum-evaporation technique. Physical and electrical properties of the films were investigated. Solution was made with a concentration of 10$^{-3}$ mol/$\ell$ using chloroform. Moving wall apparatus (NL-LB140 S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied by UV/visible absorbance spectra and morphology of surface using atomic force microscopy. Vacuum-evaporated DB-D think films were made at a pressure of 10$^{-5}$ torrr. The absorption peaks appear at 200 and 40nm in the LB films and vacuum-deposited films. And we have studied photoluminescence spectrum of the DB-D films. Also TGA and DSC properties of the DB-D have been observed and current -voltage characteristics of the DB-D LB films have been measured along the perpendicular direction.

Conducting polymer is new material in lithium secondary battery. conducting polymer has a lot of merit which is flexible and good handing so that this material is used battery system, solid polymer electrolytes airs used PEO(Polyethylene oxide) and PEO/PMMA branding material adding by liquid plasticizer or lithium salt polymer electrolyte which is added liquid plasticizer, lithium salt decreased the crystallity and thermal stability is over than 13$0^{\circ}C$. it is very useful tn apply lithium secondary battery system.

We investigated the tracking and erosion resistance of the silicone rubber by Inclined-Plane Method. And. with the variation of experiment time, the chance of the leakage current waveform was evaluated. The typical leakage current waveform was the form of mixture of sinusoidal wave and rectifying wave. It is thought that the sinusoidal wave is due to conductivity of contaminant when wet. and the rectifying wave is due to arc of dry band.

Praseodymium-based ZnO varistor containing 2.0mol% and 4.0mol% $Y_2$O$_3$ were fabricated, respectively and its microstructure and electrical properties were investigated. Yttrium distributed nearly in the grain boundaries and cluster phase at nodal point but more in cluster phase. The average grain size of the 2.0%mol% and 4.0mol% $Y_2$O$_3$-added samples was 14.8${\mu}{\textrm}{m}$ and 8.6${\mu}{\textrm}{m}$, respectively. Compared to 2.0mol% $Y_2$O$_3$, 4.0mol% $Y_2$O$_3$-added varistors showed very good I-V characteristics exhibiting highly nonlinear exponent(87.4) and low leakage current(46.7nA). These results are the important experimental fact in this paper.

The thin film that is electrically conductive and optically transparent is called conductive transparent thin film. ITO(Indium-Tin Oxide) which is a kind of conductive transparent thin film has been widely used in solar cell, transparent electrical heater, selective optical filter, FDP(Flat Display Panel) such as LCD(Liquid Crystal Display), PDP(Plasma Display Panel) and so on. Especially in PDP, ITO films is used as a transparent electrode in order to maintain discharge and decrease consumption power through the improvement of cell structure. In this study, we prepared ITO by reactive r.f. sputtering with indium-tin(Sn 10wt%) alloy target instead of indium-tin oxide target. The ITO films deposited at low temperature 15$0^{\circ}C$ and 8% $O_2$. Partial pressure showed about 3.6 Ω/$\square$. At the end of firing, the resistance of ITO was decreased, the optical transparence was improved above 90%.

In this paper, the penning effect was studded to control accelerating of the ionization that means Increasing of cross-sectional collision through penning reactions in the plasma cells of Hg-Ar-Ne (x: 10-x, 60Torr) gas discharge under various concentrations of Ar.

Recently, thiophene oligomer with short chain lengths has received much attention as model compounds for facilitating better understanding of electronic and optical properties of polymers, because oligomer is well-defined chemical systems and its conjugation chain length can be exactly controlled. Moreover, organic this films based on conjugated thiophene oligomer have potential for application to electronic and optoelectronic devices such as MISFETs(metal-insulator-semiconductor field-effect transistors) and LEDs(light-emitting diodes). However, there is little knowledge on electronic and structural properties of linear-conjugated oligothiophenes in solid states, compared with those in solutions. $\alpha$-sexithienyl($\alpha$-6T) thin-films were deposited by OMBD(Organic Molecular Beam Deposition) technique, where the $\alpha$-6T was synthesized and purified by the sublimation method. The $\alpha$-6T films were deposited under various conditions. The effects of deposition rate, substrate temperature, and vacuum pressure on the formation of these films have been studied. The molecules in the $\alpha$-6T film deposited at a low deposition rate under a high vacuum were aligned almost perpendicular to the substrate. The $\alpha$-6T films deposited at an elevated substrate temperature showed higher conductivity than the film deposited at room temperature. Electrical characterization of these films will be also executed by using four-point probe measurement technique.

TZDB(Time-Zero Dielectric Breakdown)법을 이용하여 CZ법으로 성장된 6인치완 8인치 실리콘 웨이퍼의 미세 결함에 대해 조사하였다. 80$0^{\circ}C$에서 $N_2$분위기로 성장시킨 SiO$_2$를 이용하여 표면에 1092계의 MOS 커패시터를 형성한 뒤. 개별 소자에 대해 I-V test를 행하고 이를 통해 얻이진 파괴전압과 누설전류값을 이용하여 결과를 디스플레이 하는 프로그램을 개발하였다. Breakdown실험을 토해서 얻어진 결과를 결정내부의 특성을 관찰하는 SPV결과와 비교함으로써 표면의 상태와 내부의 상태를 연관시키고자 하는 시도를 하였다. 결함이 존재하는 지역의 커패시터는 결함이 존재하지 않는 지역과 비교하여 상대적으로 높은 누설전류값을 보였다.

In this study, Eu(TTA)$_3$(phen) was synthesized and its films were prepared by vapor deposition method. Its films were characterized by UV-Vis absorption spectroscopy, Atomic Force Microscopy(AFM) and Photoluminescence(PL) measurements. Their electroluminescent(EL) characteristics were investigated by PL measurements, where a cell structure of glass substrate/ITO/Eu(TTA)$_3$(phen)/Al was employed. It was found that its films were well prepared without any decomposition and the film thickness could be controlled by adjusting the amount of Eu(TTA)$_3$(phen) in a boat. The EL spectrum of these films was almost the same as that of PL spectrum of these films.

We studied the crystallization of a-Si:H thin film. Multi-crystallized Si films are preferred in many applications such as FPD, solar cells, RAM, and integrated circuits. Because most of these applications require a low temperature process, we investigated a crystallization of a-Si:H using a Cd layer. A metal Cd shows an eutectic point at a temperature of 321$^{\circ}C$. This paper present Cd layer assisted crystallization of a-Si:H film for the various grain growth Parameters such as anneal temperature, Cd layer thickness, and anneal time