Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference (한국전기전자재료학회:학술대회논문집)
The Korean Institute of Electrical and Electronic Material Engineers
- Annual
2003.05c
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In recent years, there has been keen interest in phosphor materials responding X-ray. Cesium iodide of the materials is a material with a high
$\gamma$ -ray stopping power due to its relative high density and atomic number. CsI is noted for its high resistance to thermal and mechanical shock due to the absence of a cleavage plane. To design the structure of CsI detector, we analysed the structure with SEM and XRD and measured UV meter. -
For use in constructing highly sensitive thermal detectors, the present authors have been studying the preparation of Superconducting Flux Flow Sensor(SFFS). In this research, SFFS with five channel (
$5{\mu}m$ /1channel) has been fabricated based on the flux flow using high temperature superconducting thin films by the ICP etching technique. We have designed a bolometer based on the temperature dependence of the kinetic inductance of a superconducting flux flow thin film. In this paper examines the fabrications and flux flow resistance and thermometer responses of the highly sensitive sensor constructed of a thin YBCO film. It is also suggested that they will be applicable to a new type of flux flow sensor. -
Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency
$({\Delta}F)$ and resonant resistance(R). The redox process of viologen was observed with resonant frequency$({\Delta}F)$ . -
본 논문은 시료의 양을 최소화하고 혈중 요소 및 혈당 농도에 대한 정확한 측정을 위하여 최근에 개발된 전기화학형 마이크로 전극형 센서의 간략한 소개 및 전기적인 특성에 관하여 요약하는 것에서 출발하여 센서로부터 전기신호를 발생시키는 signal conditioning 회로의 설계, microprocessor를 이용한 digital 값으로의 변환 및 data 취득, 취득한 data를 측정된 혈당량 및 요소량으로의 변환 저장 display까지의 휴대용 계측기의 prototype 개발에 관하여 기술한다. 이 계측기는 미량의 혈액채취 한번으로 농도를 측정하는 측정모드와, 측정된 data를 찾아보기 위한 검색모드로 작동시킬 수 있다. Microprocessor의 기능을 최대한 사용하여 측정기의 크기를 소형화하였으며 LCD(Liquid crystal display)틀 채택하는 등 저전력 회로로 구현하였다.
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Role of oxidant on polishing selectivity in the chemical mechanical planarization of W/Ti/TiN layersTungsten is widely used as a plug for the multi-level interconnection structures. However, due to the poor adhesive properties of tungsten (W) on
$SiO_2$ layer, the Ti/TiN barrier layer is usually deposited onto$SiO_2$ for increasing adhesion ability with W film. Generally, for the W-CMP (chemical mechanical polishing) process, the passivation layer on the tungsten surface during CMP plays an important role. In this paper, the effect of oxidants controlling the polishing selectivity of W/Ti/TiN layer were investigated. The alumina$(Al_2O_3)$ abrasive containing slurry with 5 %$H_2O_2$ as the oxidizer, was studied. As our preliminary experimental results, very low removal rates were observed for the case of no-oxidant slurry. This low removal rate is only due to the mechanical abrasive force. However, for Ti and TiN with 5 %$H_2O_2$ oxidizer, different removal rate was observed. The removal mechanism of Ti during CMP is mainly due to mechanical abrasive, whereas for TiN, it is due to the formation of metastable soluble peroxide complex. -
As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP) process was required for the global planarization of inter-metal dielectric (IMD) layer with free-defect. However, as the IMD layer gets thinner, micro-scratches are becoming as major defects. Micro-scratches are generated by agglomerated slurry, solidified and attached slurry in pipe line of slurry supply system. It is well known that the presence of hard and larger size particles in the CMP slurries increases the defect density and surface roughness of the polished wafers. In this paper, we have studied aging effect the of CMP slurry as a function of particle size. We prepared and compared the self-developed silica slurry by adding of abrasives before and after annealing. As our preliminary experiment results, we could be obtained the relatively stable slurry characteristics comparable to original silica slurry in the slurry aging effect.
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As the device feature size is reduced to the deep sub-micron regime, the chemical mechanical polishing (CMP) technology is widely recognized as the most promising method to achieve the global planarization of the multilevel interconnection for ULSI applications. However, cost of ownership (COO) and cost of consumables (COC) were relatively increased because of expensive slurry. In this paper, the effects of different slurry composition on the oxide CMP characteristics were investigated to obtain the higher removal rate and lower non-uniformity. We prepared the various kinds of slurry. In order to save the costs of slurry, the original slurry was diluted by de-ionized water (DIW). And then, alunima abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry.
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The polishing mechanism of W-CMP process has been reported as the repeated process of passive layer formation by oxidizer and abrasion action by slurry abrasives. Thus, it is important to understand the effect of oxidizer on tungsten passivation layer in order to obtain higher removal rate (RR) and very low non-uniformity (NU%) during W-CMP process. In this paper, we investigated the effects of oxidizer on W-CMP process with three different kinds of oxidizers, such as
$H_2O_2$ ,$Fe(NO_3)_3$ , and$KIO_3$ . In order to compare the removal rate and non-uniformity of three oxidizers, we used alumina-based slurry of pH 4. According to the CMP tests, three oxidizers showed different removal mechanism on tungsten surface. Also, the microstructures of surface layer by AFM image were greatly influenced by the slurry chemical, composition of oxidizers. The difference in removal rate and roughness of tungsten surface are believed to caused by modification in the mechanical behavior of$Al_2O_3$ abrasive particles in CMP slurry. Our stabilized slurries can be used a guideline and promising method for improved W-CMP process. -
The role of gas ratio with the crystallization behavior and electrical properties in
$Bi_{3.25}La_{0.75}Ti_3O_{12}$ (BLT) thin films by rf magnetron sputtering method has not been precisely defined. In this work, the ferroelectric properties of these films with gas variation was investigated. BLT thin films were deposited on the Pt/Ti bottom electrode by rf magnetron sputtering method and then they were crystallized by rapid thermal annealing (RTA). The experiment showed that all BLT films indicated perovskite polycrystalline structure with preferred orientation (020) and (0012). And no pyrochlore phase was observed. The fabricated film annealed with$O_2$ of 15 sccm showed that value of leakage current was$9.67{\times}10^{-7}A/cm^2$ at 50kV /em, and the value of remanent polarization (2Pr=Pr+-Pr-) was$11.8{\mu}C/cm^2$ . Therefore we induce access to memory device application by rf-magnetron sputtering method in this report. -
The properties of YBCO thick film coated on Ag wire with YBCO powder is deeply affected by cracking on its surface which was deposited in organic solution by electrophoretic method. YBCO superconducting thick films were prepared on Ag wire
$({\Psi}0.8mm)$ by electrophoresis in acetone with added PEG (Poly-Ethylene Glycol, 3% in Acetone), 1ml for being crack-free. The surface properties of YBCO superconducting wire was evidently improved with adding PEG. Added PEG which molecular weight is 600, 1000, 3400 was affected with variation of deposition voltages to the surface properties of samples. As a result, with adding PEG (its molecular weight is 3400), YBCO superconducting wire was better on its surface properties. -
This paper describes the modeling and simulation results for film bulk acoustic resonators(FBAR). We present the frequency tuning mechanisms, analytical solutions of the wave equation and the influence of the thickness of the electrodes. The impedance for PZT based FBAR is derived utilizing proper boundary conditions and their material parameters. Ferroelectrics-based RF filter composed of FBARs are designed.
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A magnetic field sensor is fabricated with superconducting ceramics system The prepared material shows the superconductivity at about 95K. The sensor at liquid nitrogen temperature shows the increase in electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor is changed from zero to a value more than
$100{\mu}V$ by the applied magnetic field. The change in electrical resistance depends on magnetic field. The sensitivity of this sensor is 2.9 ohm/T. The increase in electrical resistance by the magnetic field is ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material. -
단원계 및 이원계 촉매를 이용하여 나노 감지 소자를 합성하였고, 이를 이용하여 가연성 후막 가스 센서를 제작, 촉매 시스템에 따른 가스 감지 특성을 비교하였다. 단원계의 경우 Pd 및 Pt를 각각 3wt%로, 이원계의 경우 Pd:Pt 농도를 1:2~2:1wt%로 각각 제어하여 평균 입도가 15 nm 인
$SnO_2$ 나노 분말에 도핑, 감지물질을 합성하였다. 그 후 감지물질을 paste로 만들어 인쇄, 가스센서 제작 후$450{\sim}600^{\circ}C$ 의 온도로 열처리하였다. 그 결과 이원계 촉매 시스템을 가진 가스 센서는 시효 시간에 따라 감도 값이 변하는 불안정한 현상을 나타내었다, 그러나 단원계 촉매의 경우 시효 시간이 지나도 감도 값이 안정된 현상을 나타내었다. 특히 3wt% pt를 도핑하여$500^{\circ}C$ 에서 열처리한 경우 5시간 시효 후에도 감도 값의 변화 폭이 3.5% 이하의 매우 안정된 특성을 나타내었고 반응 시간도 20초 이하로 매우 빠른 응답 특성을 나타내었다. -
Photoconductor for direct detection fiat-panel imager present a great materials challenge, since their requirement include high X-ray absorption, ionization and charge collection, low leakage current and large area deposition, CdTe is practical material. We report studies of detector sensitivity, That is an CdTe with
$5{\mu}m$ thickness on glass. That is hybrid layer of depositting ZnS:AgCl phosphor with$100{\mu}m$ on CdTe. The leakage current of hybrid is similar to it of a-Se, but photocurrent is larger than a-Se. Both of them have high spatial resolution, but hybrid has higher sensitivity than a-Se at comparable bias voltage. -
In recent years, there has been keen interest in developing flat panel detectors for all modalities of radiology, including gerneral radiology, fluoroscopy, electronic portal imaging, and mammography. In this paper, we report the new hybrid x-ray detector consisted of ZnS(Ag) photoemission layer and a-Se photoconductor layer to resolve problem of conventional x-ray detector such as the direct detector and the indirect detector. To design the structure of ZnS(Ag)/a-Se detector, the penetrated energy spectrum and absorption fraction was estimated using MCNP 4C code. Also, we carried out the experiment to demonstrate the result of MCNP 4C code. Experimental results showed that the absorption fraction of
$500{\mu}m$ -ZnS(Ag) film was above 87%, 75% at 60 and 80 kVp. As a results, we can determined the thickness of suitable phosphor and the thickness of photoconductor. -
a-Se film is known as promising medical X-ray detector material but a-Se as dopanted Tellurium is not available in X-ray detectors. a-Se thick film was grown by vacuum thermal evaporator to
$3{\mu}m$ thickness. The characteristics of thick films were analyzed by XRD, U-V Meter, and SEM measurements. Te composition is 0.1, 0.3, 0.5, 0.7g. This paper is fundmental data for phosphor layer's essential parameter that selenium have absorption wavelength along to various Te concentration rate. -
Thin films of amorphous carbon (a-C) generally combine high wear resistance with low friction coefficients and a-C films have widespread applications as protective coatings and passivation of electrical circuit and insulating layer. In this work we deposited the amorphous carbon (a-C) films on silicon substrate with a high rate DC magnetron sputtering system. It is obtained parameters on the deposition rate and physical properties of a-C films using a wide range of Ar gas pressure and DC power. The physical properties of the films were analyzed by Nanoindenter and AFM (Atomic Force Microscopy), The electrical properties were investigated by electrical conductivity measurement.
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The purpose of this study is to research and develop tin oxide-flash composite for lithium Ion polymer battery. Tin oxide is one of the promising material as a electrode active material for lithium Ion polymer battery (LIPB). Tin-based oxides have theoretical volumetric and gravimetric capacities that are four and two times that of carbon, respectively. We investigated cyclic voltammetry and charge/discharge cycling of SnO-flyash/SPE/Li cells. The first discharge capacity of SnO-flyash composite anode was 720 mAh/g. The discharge capacity of SnO-flyash composite anode 412 and 314 mAh/g at cycle 2 and 10 at room temperature, respectively. The SnO-flyash composite anode with PVDF-PMMA-PC-EC-
$LiClO_4$ electrolyte showed good capacity with cycling. -
The purpose of this project is to research and development of thin film supercapacitor with conducting polymer composite electrodes and polymer electrolyte which have high energy density for thin film supercapacitor. We investigated cyclic voltammetry and charge/discharge cycling of PFPT-flyash electrodes. The first discharge capacity of PFPT-flyash electrode with 40wt.% flyash was 24F/g, while that of PFPT-VOflyash electrode with 40wt.% VOflyash was 32F/g. The capacitance of PFPT-VOflyash composite film with polymer electrolyte was 32 F/g at 1st and 20th cycle, respectively. The capacitance of PFPT-VOflyash/Li cell with 40 wt% VOflyash was 141 F/g at 8th cycle.
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Tin doped indium oxide(ITO) films, which is widely used as a transparent conductor in optoelectronic devices such as solar cell, liquid crystal display, plasma display panel, thermal heater, and other sensors, were prepared by using the capacitively coupled DC magnetron sputtering method. The influence of the substrate temperature, working gas pressure and deposition time on the electrical, optical and morphological properties were investigated experimentally. ITO films with the optimum growth conditions showed resistivity of
$2.36{\times}10^{-4}(\Omega}-cm$ and transmittance of 86.28% for a film 680nm thick in the wavelength range of the visible spectrum. -
Tin dioxide thin films were deposited at
$375^{\circ}C$ on alumina substrate by metal-organic chemical vapor deposition process to find the relationship between physicochemical properties and the annealing treatments. The small grains with heat treatments grew to the bunch of grains and then showed the hillocks on the film surface. The thickness decreased with annealing treatment. The measured binding energy (BE) and branching ratio of the Sn 3d spin-orbital doublet were typical of oxidized states of Sn and the BE of the O1s core level of about 530~530.65eV also confirmed the presence of O-Sn bonds. The BE of oxygen and tin with annealing treatment shifted to higher position. O/Sn atomic ratios of films deposited at$375^{\circ}C$ for 2min and 4min were 1.99 and 2.01, respectively. The value of the atomic ratio O/Sn of films deposited at$375^{\circ}C$ for 2min changed from 1.99 to 2.45 with annealing treatment. Gas sensitivity depended on annealing temperature, the sensitivity increased with increasing annealing temperature. -
It is well known that the state of existence of molecules on the surface of water changes during compression of the molecules. Electric methods, such as measurement of the surface potential or displacement current are also useful for investigating dynamic changes of molecular state on the water surface during compression. In this paper, We studied on the Bio thin film by Langmuir-Biodgett(LB) method. The Experiment method used displacement current,
$\pi-A$ isotherm and BAM (Brewster Angle Microscopy). using the BAM, we can to the molecular orientation of monolayer on the water surface and directly see the morphology of the films on water subphase as well as that of the films. -
In this paper, We introduced that the method for determing the dielectric relaxation time
$\tau$ of floating monolayers on water interface. Displacement current flowing across monolayers is analyzed using a rod-like molecular model. It is revealed that the dielectric relaxation time$\tau$ of monolayers in the isotropic polar orientational phase is determined using a linear relationship between the monolayer compression speed$\alpha$ and the molecular area Am. here Displacement current gives a peak at A = Am. The dielectric relaxation time$\tau$ of organic monolayers was examined on the basis of the analysis developed here. -
200nm 정도의 두께를 가진 SBT 박막이 liquid delivery MOCVD 공정에 의해 (111) oriented Pt/Ti/
$SiO_2$ /Si 기판 위에 증착되었다 이 실험에서는$Sr(TMHD)_2$ tetraglyme,$Bi(ph)_3$ 그리고$Ta(O^iPr)_4$ (TMHD)를 출발 물질로 사용하였다. Sr 출발 물질의 열적 안정화를 위해서 adduct로 tetraglyme를 사용하여 실험하였고 유기 용매로는 n-butyl acetate를 사용하였다 Substrate temperature와 reactor pressure는 각각$570^{\circ}C$ 와 5Torr로 유지시켰다. 또한 vaporizer의 용도는$190-200^{\circ}C$ , 그리고 delivery line 의 온도는 vaporizer 보다 높게 유지$(220-230^{\circ}C)$ 하여 출발 용액을 분당 0.1ml로 50분간 주입하였다. 수송가스로 Ar, 산화제로$O_2$ 가스를 사용하였다. 제조한 SBT 박막은$750^{\circ}C$ 에서 열처리한 후 인가전압 3V와 5V에서$2P_r$ 값이 각각 6.47,$8.98{\mu}C/cm^2$ 이었으며,$2E_c$ 값은 인가전압 3V와 5V에서 각각 2.05, 2.31V이었다 그리고$800^{\circ}C$ 에서는$750^{\circ}C$ 에서 열처리한 SBT 박막보다 다소 우수한 이력특성을 나타내어$2P_r$ 값은 인가전압 3V와 5V에서 각각 7.59,$10.18{\mu}C/cm^2$ 이었으며,$2E_c$ 값은 인가 전압 3V와 5V에서 각각 2.00, 2.21V 이었다. -
Self-patterning of thin films using photosensitive sol solution has advantages such as simple manufacturing process compared to photoresist/dry etching process. In this study, ferroelectric
$Sr_{0.9}Bi_{2.1}Ta_2O_9$ (SBT) and$La_{0.5}Sr_{0.5}CoO_3$ (LSCO)thin films have been prepared by spin coating method using photosensitive sol solution.$Sr(OC_2H5)_2$ ,$Bi(TMHD)_3$ and$Ta(OC_2H)_5)_5$ were used as starting materials for SBT solution and$La(OCH_2CH_2OCH_3)_3$ ,$Sr(OC_2H_5)_2$ ,$CO(OCH_2CH_2OCH_3)_2$ were used for LSCO solution. Solubility difference by UV irradiation on LSCO thin film allows to obtain a fine patterning due to M-O-M bond formation. The lowest resistivity($4{\times}10^{-3}{\Omega}cm$ ) of LSCO thin films was obtained by annealing at$740^{\circ}C$ . -
To investigate the characteristics of the single dendrimer molecule, we attempt to measure morphology and electrical properties of the self-assembled dendrimer on Au (111)substrate with SPM(scanning probe microscopy). The same self-assembly procedure was used for two different concentrations,
$10{\mu}mol/ml$ and$100{\mu}mol/ml$ . The case of lower concentration, we can measure the diameter and the height of the single molecule with the tapping mode AFM image. The imaged single molecules were dome shaped and the average diameter and height were 15.6 nm, 1.2 nm respectively. From these sizes, we can calculate the volume of the single molecule. The volume of the single molecule was estimated about$116nm^3$ . However, that of higher concentration, it is difficult to obtain obvious image of the single molecule. To add to, I-V characteristics were investigated using STM, on which the phenomenon of negative differential resistance (NDR)was observed between 0.14 V and 0.24 V reproductively. -
Zinc Oxide(ZnO) thin films on Si (100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance. To analyze a crystallographic properties of the films,
$\theta/2\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity. and surface roughness highly depended on$Ar/O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of$9{\times}10^7{\Omega}cm$ was obtained at a working pressure of 10 mTorr with$Ar/O_2$ =50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with$Ar/O_2$ =50/50 showed the excellent roughness value of$28.7{\AA}$ . -
Zinc Oxide(ZnO) thin films on Si (100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance. To analyze a crystallographic properties of the films,
$\theta/2\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity, and surface roughness highly depended on$Ar/O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of$9{\times}10^7{\Omega}cm$ was obtained at a working pressure of 10 mTorr with$Ar/O_2$ =50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with$Ar/O_2$ =50/50 showed the excellent roughness value of$28.7{\AA}$ . -
Cu+ ions drift diffusion in different dielectric materials is evaluated. The diffusion is investigated by measuring shift in the flatband voltage of capacitance/voltage measurements on Cu gate capacitors after bias temperature stressing. At a field of 1.lMV/cm and temperature
$200^{\circ}C$ ,$250^{\circ}C$ ,$300^{\circ}C$ for 1H, 2H, 5H. The Cu+ ions drift rate of polyimide$(2.8{\leq}k{\leq}3.2)$ is considerably lower than thermal oxide. Also Cu+ drift rate of polyimide is similar to PECVD oxide. But, polyimide film is even more resistant to Cu drift diffusion and thermal effect than Thermal oxide, PECVD oxide: This results got a comparative reference. The important conclusion is that polyimide film is strongly dielectric material by thermal effect and Cu drift diffusion. -
This study proposes ZnO thin film as a piezoelectric material for SAW (surface acoustic wave) filter. The ZnO thin film with thickness
$2.6{\mu}m$ was deposited (0001)-oriented sapphire by RF magnetron sputtering technique. IDTs (inter-digital transducers) electrodes were patterned upon SAW filter mask with solid finger structure unapodized using lift-off method on ZnO piezoelectric thin film. SAW propagation velocity was measured with the center frequency by HP 8753C network analyzer. A fabricated ZnO SAW filter exhibited a high propagation velocity of 5433$^m/s$ and relatively insertion loss of -53.391dB at$\lambda=80{\mu}m$ . The side-lobe attenuation of the center frequency was about 17dB. When the wavelength was$80{\mu}m$ $(\lambda/4=20{\mu}m)$ , the center frequency was 67.907 MHz.$k^2$ (electromechanical coupling coefficient) was 15.84 %. -
Park, Sung-Woo;Seo, Yong-Jin;Kim, Gi-Uk;Choi, Woon-Sik;Kim, Chul-Bok;Kim, Sang-Yong;Lee, Woo-Sun 145
Recently, the recycle of CMP (chemical mechanical polishing) slurries have been positively considered in order to reduce the high COO (cost of ownership) and COC (cost of consumables) in CMP process. Among the composition of slurries (buffer solution, bulk solution, abrasive particle, oxidizer, inhibitor, suspension, antifoaming agent, dispersion agent), the abrasive particles are one of the most important components. Especially, the abrasive particles of slurry are needed in order to achieve a good removal rate. However, the cost of abrasives, is still very high. In this paper, we have collected the silica abrasive powders by filtering after subsequent CMP process for the purpose of abrasive particle recycling. And then, we have studied the possibility of recycle of reused silica abrasive through the analysis of particle size and hardness. Also, we annealed the collected abrasive powders to promote the mechanical strength of reduced abrasion force. Finally, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and original slury, As our experimental results, we obtained the comparable removal rate and good planarity with commercial products. Consequently, we can expect the saving of high cost slurry. -
Chemical mechanical polishing (CMP) technology for global planarization of multi-level inter-connection structure has been widely studied for the next generation devices. CMP process has been paid attention to planarized pre-metal dielectric (PMD), inter-layer dielectric (ILD) interconnections. Expecially, shallow trench isolation (STI) used to CMP process on essential. Recently, the direct STI-CMP process without the conventional complex reverse moat etch process has established by using slurry additive with the high selectivity between
$SiO_2$ and$Si_3N_4$ films for the purpose of process simplification and n-situ end point detection(EPD). However, STI-CMP process has various defects such as nitride residue, tom oxide and damage of silicon active region. To solve these problems, in this paper, we studied the planarization characteristics using a high selectivity slurry(HSS). As our experimental results, it was possible to achieve a global planarization and STI-CMP process could be dramatically simplified. Also we estimated the reliability through the repeated tests with the optimized process conditions in order to identify the reproducibility of HSS STI-CMP process. -
$TiO_2$ thin films were fabricated by RF magnetron sputtering system at by controlling deposition times, ratios of$Ar:O_2$ partial presser ratio and substrate conditions. And the surface, cross-section morphology, microstructure, and composition ratio of the films were analyzed by FE-SEM, TEM and XPS. Besides, the optical absorption and transmittance of the$TiO_2$ films were measured by a UV-VIS-NIR Spectrophotometer, and photocatalytic properties were studied by G${\cdot}$ C Analyzer & Data Analysis system. As the result, when$TiO_2$ thin film was made at deposition time of 120[min] and$Ar:O_2$ ratio of 60:40, the best structural and optical properties among many thin films could be accepted. The best results of properties were as follows: thickness; 360~370[nm), grain size; 40[nm], gap between two peak binding energy;$5.8{\pm}0.05[eV]$ ($2_{p3/2}$ peak and$2_{p1/2}$ peak of Ti was show at$458.3{\pm}0.05[eV]$ and$464.1{\pm}0.05[eV]$ respectively), binding energy;$530{\pm}0.05[eV]$ , optical energy band gap; 3.4[eV]. -
The primary aim of this study is to investigate new semi-abrasive free slurry including acid colloidal silica and hydrogen peroxide for copper chemical-mechanical planarization (CMP). In general, slurry for copper CMP consists of colloidal silica as an abrasive, organic acid as a complex-forming agent, hydrogen peroxide as an oxidizing agent, a film forming agent, a pH control agent and several additives. We developed new semi-abrasive free slurry (SAFS) including below 0.5% acid colloidal silica. We evaluated additives as stabilizers for hydrogen peroxide as well as accelerators in tantalum nitride CMP process. We also estimated dispersion stability and Zeta potential of the acid colloidal silica with additives. The extent of enhancement in tantalum nitride CMP was verified through anelectrochemical test. This approach may be useful for the application of single and first step copper CMP slurry with one package system.
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The corrosion characteristics of diffusion barrier in Copper CMP has been investigated. Key experimental variables that has been investigated are the corrosion rate by different agents containing slurry of Cu CMP. Whenever Cu and Ta films were corroded adding each oxidizer, the corrosion rate of Ta was much lower than that of Cu. That is, the difference in the corrosion rates of Ta by oxidizer was not larger as compared with Cu. As corroded by complexing agents, the corrosion rate of Ta was close to O. The corrosion rate of Ta increased as added
$HNO_3$ and$CH_3COOH$ compared with the reference slurry; on the other hand, it decreased with addition of HF. In addition, resulting corrosion rate went up with lower pH of agent. The corrosion rates by agents were however significant small; hence, it doesn't affect on the removal rate of Cu CMP practically. Consequently, this can be explained by assuming that the mechanical effect dominates than the chemical effect on the polishing rate of Ta(TaN). -
In this study, we evaluated the characteristics by the addition of 3 different kinds of nonionic surfactant to improve the dispersion stability of slurries. Slurry stability is an issue in any industry in which settling of particles can result in poor performance. So we observed the variation of particle size and settling rate when the concentration and addition time of surfactant are changed. When the surfactant is added after milling process, the particle size and pH became low. It is supposed that the particle agglomeration was disturbed by adsorption of surfactant on alumina abrasive. The settling rate was relatively stable when nonionic surfactant is added about 0.1~1.0 wt%. When molecular weight(MW) is too small like Brij 35, it was appeared low effect on dispersion stability. Because it can't prevent coagulation and subsequent settling with too small MW. The proper quality of MW for slurry stability was presented about 500,000. Consequently, the addition of nonionic surfactant to alumina slurry has been shown to have very good effect on slurry stabilization. If we apply this results to copper CMP process, it is thought that we will be able to obtain better yield.
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In this paper, we proposed a new bulk LDMOS structure which can be used for RF application, and its fabrication steps were introduced. The simulated devices consist of three types: Bulk device, SLB(SOI Like Bulk), and SOI device. As a result of process and device simulation, we showed electrical characteristics, such as threshold voltage, subthreshold slope, DIBL(Drain Induced Barrier Lowering), off-state current, and breakdown voltage. In this simulation study, the lattice temperature model was adopted to see the device characteristics with lattice temperature during the operation. SLB device structure showed the best breakdown characteristics among the other structures. The breakdown voltage of SLB structure is about 9V, that of bulk is 7V, and that of SOI is 8V.
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$Cl_2$ 플라즈마를 이용한 BLT 박막의 식각에서 Ar 가스의 첨가에 따른 식각 속도, 선택비 및 식각 형상의 변화에 대하여 관찰하였다. BLT 박막의 식각 속도는 100% Ar 플라즈마에서 100 %$Cl_2$ 플라즈마에서의 식각 속도보다 약 1.5배정도 빨랐으며, 80% Ar/20%$Cl_2$ 조건에서$503{\AA}/min$ 최대 식각의 최대 시각 속도를 얻었다. RF 전력과 직류 바이어스 전압을 증가함에 따라 식각 속도는 증가하였으며,$Ar/Cl_2$ 플라즈마의 식각 속도가$Cl_2$ 플라즈마의 식각 속도 보다 높았다. 식각 공정 변수의 변화에 의한 플라즈마 변수가 BLT 식각 속도에 미치는 영향을 관찰하기 위하여 LP(Lanmuir porbe)와 OES(optical emission spectroscopy)분석을 수행하였다. Ar 첨가량이 증감함에 따라 LP 분석에서 전자의 온도는 증가하였으나 전자밀도는 감소하였다. 이는 Ar의 이온화 준위가 Cl 보다 높기 때문에 이온화 윷이 낮아지기 때문으로 판단된다, 또한, OES 분석에서 Ar 첨가량이 증가함에 따라 Cl 원자의 부피 밀도는 감소하였다. Ar 첨가에 의한 BLT 박막의 식각 속도의 변화와 LP 및 OES 분석을 고려하면, BLT 박막은 화학적 식각의 도움을 받는 무리적 식각에 의하여 식각됨을 확인하였다, -
In this work, we etched PZT films with various additive gases (
$O_2$ and Ar) in$Cl_2/CF_4$ plasmas, while mixing ratio was fixed at 8/2. After the etching, the plasma induced damages are characterized in terms of hysteresis curves, leakage current, retention properties, and switching polarization. When the electrical properties of PZT etched in$O_2$ or Ar added$Cl_2/CF_4$ were compared, the value of remanent polarization in$O_2$ added$Cl_2/CF_4$ plasma is higher than that in Ar. added plasma. The maximum etch rate of the PZT thin films was 145 nm/min for 30% Ar added$Cl_2/CF_4$ gas having mixing ratio of 8/2 and 110 nm/min for 10%$O_2$ added to that same gas mixture. In order to recover the ferroelectic properties of the PZT thin films after etching, we annealed the etched PZT thin films at$550^{\circ}C$ in an$O_2$ atmosphere for 10 min. From the hysteresis curves, leakage current, retention property and switching polarization, the reduction of the etching damage and the recovery via the annealing was turned out to be more effective when$O_2$ was added to$Cl_2/CF_4$ than Ar. X-ray diffraction (XRD) showed that the structural damage was lower when$O_2$ was added to$Cl_2/CF_4$ . And the improvement in the ferroelectric properties of the annealed samples was consistent with the increased intensities of the (100) and the (200) PZT peaks. -
Etching characteristics of (PB,Sr)
$TiO_3$ (PST) thin films Were investigated using inductively coupled chlorine based plasma system as functions of gas mixing ratio, RF power and DC bias voltage. It was found that increasing of Ar content in gas mixture' lead to sufficient increasing of etch rate and selectivity of PST to Pt. The maximum etch rate of PST film is 562${\AA}$ /min and the selectivity of PST film to Pt is 0.8 at$Cl_2/(Cl_2+Ar)$ of 20 %. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products. -
The MFIS capacitors were fabricated using a metalorganic decomposition method. Thin layers of
$ZrO_2$ and$CeO_2$ were deposited as a buffer layer on Si substrate and BLT thin films were used as a ferroelectric layer. The electrical and structural properties of the MFIS structure were investigated. X -ray diffraction was used to determine the phase of the BLT thin films and the quality of the$ZrO_2$ and$CeO_2$ layer. AES show no interdiffusion and the formation of amorphous$SiO_2$ layer is suppressed by using the$ZrO_2$ and$CeO_2$ film as buffer layer between the BLT film and Si substrate. The width of the memory window in the C-V curves for the$BLT/ZrO_2/Si$ and$BLT/CeO_2/Si$ structure is 2.94 V and 1.3V, respectively. The experimental results show that the BLT-based MFIS structure is suitable for non-volatile memory FETs with large memory window. -
Sm-doped lead zirconate titanate(
$Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_3$ ; PZT) thin films on the Pt(111)/Ti/$SiO_2$ /Si(100) substrates prepared by a sol-gel method. The effect on structural and electrical properties of PZT thin films measured according to the Sm content. Sm-doping altered significantly dielectric and ferroelectric properties. The remanent polarization and the coercive field decreased with the increasing Sm content. The dielectric constant and the dielectric loss of PZT thin films decreased with the increasing Sm content. At 100 kHz, the dielectric constant and the dielectric loss of. the 0.3 mol% of Sm-doped PZT thin film were 1200 and 0.12 respectively. The remanent polarization (2Pr) of the 0.3 mol% of Sm-doped PZT thin film was$52.13{\mu}C/cm^2$ and the coercive field was 94.01 kV/cm. The 0.3 mol% of Sm-doped PZT thin film showed an improved fatigue characteristic comparing to the undoped PZT thin film. -
Depth error correction effect for maladjusted stereo cameras with calibrated pixel distance parameter is presented. The proposed neural network technique is the real time computation method based theory of inter-node diffusion for searching the safety distances from the sudden appearance-objects during the work driving. The main steps of the distance computation using the theory of stereo vision like the eyes of man is following steps. One is the processing for finding the corresponding points of stereo images and the other is the interpolation processing of full image data from nonlinear image data of objects. All of them request much memory space and time. Therefore the most reliable neural-network algorithm is derived for real-time matching of objects, which is composed of a dynamic programming algorithm based on sequence matching techniques.
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Ferroelectric europium-substitution
$Bi_4Ti_3O_{12}$ thin films were fabricated by spin-coating onto a Pt/Ti/$SiO_2$ /Si substrate. The$Bi_{3.25}Eu_{0.75}Ti_3O_{12}$ (BET) films have polycrystalline structure annealed at 700 C. We investigated that the influence of$Bi_4Ti_3O_{12}$ thin films by substituting for Bi ions with Bi ions using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). From the XPS measurement, it was suggested that the stability of the metal-oxygen octahedral should be related to substitute for Bi ions with Eu ions at annealed$800^{\circ}C$ . The BET thin films showed a large remanent polarization (2Pr) of$60.99C/cm^2$ at an applied voltage of 10 V. The BET thin films exhibited no significant degradation of switching charge at least up to$5{\times}10^9$ switching cycles at a frequency of 50 kHz. -
The flip chip bonding utilizing self-aligning characteristic of solder becomes mandatory to meet to tolerances for the optical device. In this paper, a parametric study of aging condition and pad size of sample was conducted. A TiW/Cu UBM structure was adopted and sample was aging treated to analyze the effect of intermetallic compound with time variation. After aging treatment, the tendency to decrease in shear strength was measured and the structure of the fine joint area was observed by using SEM, TEM and EDS. In result, the shear strength was decreased of about 20% in the
$100{\mu}m$ sample at$170^{\circ}C$ aging compared with the maximum shear strength of same pad size sample. In the case of the$120^{\circ}C$ aging treatment, 17% of decrease in shear strength was measured at the$100{\mu}m$ pad size sample. Also, intremetallic compound of$Cu_6Sn_5$ and$Cu_3Sn$ were observed through the TEM measurement by using an FIB technique that is very useful to prepare TEM thin foil specimens from the solder joint interface. -
Silicon transient voltage suppressors (TVSs) are clamping devices that limit voltage spikes by low impedance avalanche breakdown of a rugged silicon PN junction. They are used to protect sensitive components from electrical overstress such as that caused by induces lightning, inductive load switching and electrostatic discharge. In this paper, we present static and dynamic characteristics of TVS diode using thermal analysis simulation software. And also, it is presented that the thermal dissipation characteristics of TVS diode in the transient state.
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Recently a new high power device GCT (Gate Commutated Turn-off) thyristor has been successfully introduced to high power converting application areas. GCT thyristor has a quite different turn-off mechanism to the GTO thyristor. All main current during turn-off operation is commutated to the gate. Therefore, IGCT thyristor has many superior characteristics compared with GTO thyristor; especially, snubberless tum-off capacibility and higher turn-on capacibility. The basic structure of the GeT thyristor is same as that of the GTO thyristor. This makes the blocking voltage higher and controllable on-state current higher. The turn-off characteristic of the GCT thyristor is influenced by the minority carrier lifetime and the performance of the gate drive unit. In this paper, we present turn-off characteristics of the 2.5kV PT(Punch-Through) type GCT as a function of the minority carrier lifetime and variation of the doping profile shape of p-base region.
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$0.2(PbMg_{1/3}Nb_{2/3}O_3)-0.8(PbZr_{0.475}Ti_{0.525}O_3)$ 조성을 이용하여$5{\times}5{\times}5mm^3$ 의 적층형 세라믹 액츄에이터 소자를 tape casting 방법으로 제작하였다. 전극재로서는 Ag-Pd를 이용하여 총 50층의 layer를 적층하였으며, 적층된 액츄에이터를$1100^{\circ}C$ 의 온도에서 소결하였다. X-ray diffractometer를 이용하여 제작된 소자와 열화된 소자의 구조적인 특성을 분석하였다. 제작된 소자의 열화 특성을 알아보기 위하여 60 Hz 의 triangular wave를 인가하여 열화전과 후의 p-E hystcresis loop의 변화를 살펴보았으며, 인가된 전압의 변화에 따라서 소자에서 발생되는 양의 열을 측정하였다. 파괴된 소자의 파단면에 대한 SEM 분석을 통하여 소자의 파괴 메카니즘을 알아보도록 하였다. 이로부터 전기적 기계적 열화가 소자의 동작에 미치는 영향에 대해서 알아 보았다. -
In this study, ultrasonic rotary motors using a bolted langevin type ultrasonic vibrator were designed and fabricated. The stator vibrator has a longitudinal transducer section composed of two metal blocks and two piezoelectric ceramic elements (thickness-polarized) and a mode conversion metal block section called a torsion coupler. And, three kinds of motors were studied by finite element analysis and experiments. So, as material of torsion coupler which generate mode conversion of vibration copper, brass, and phosphor bronze were used. As a result, speed and torque were changed in proportion to the electrical input Voltage, but it was saturated in high voltage. And bad efficiency which was different from a expectation was measured in this motors. So, various problems should be improved for practical use. Finally, The motor which has 1 [cm] diameter was fabricated to present a possibility of miniaturization of this type motors.
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In this sturdy, piezoelectric transformer using PNW-PMN-PZT ceramics was fabricated with the size of
$1{\times}16{\times}5mm^3$ for LCD backlight inverter application of PDA. And its electrical characteristics were investigated with load resistance and driving frequency. At the frequency of 212.6kHz, CCFL for PDA was driven stably, and input voltage of 8.83V and output voltage of 305V were shown. -
In this study, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, dielectric and piezoelectric properties of PSN-PZT ceramics were investigated as a function of CuO addition, At the 0.6wt% CuO added specimen sintered at
$920^{\circ}C$ , the most excellent mechanical quality factor and electromechanical coupling factor were obtained. -
In this study, to develop the low temperature sintering ceramics for piezoelectric transformer, PSN-PNN-PZT system ceramics were manufactured as a function of
$MnO_2$ addition. Its dielectric and piezoelectric characteristics were investigated. With increasing the amount of$MnO_2$ addition, electromechanical coupling factor(kp) were increased until 0.3wt%$MnO_2$ and that after decreased. mechanical quality factor(Qm) showed the maxinum value at 0.5wt%$MnO_2$ . For piezoelectric transformer application, the 0.5wt%$MnO_2$ added specimen sintered at$1,000^{\circ}C$ showed the proper value of${\varepsilon}r$ = 1,646, kp=0.55 and Qm=439. -
후막 리소그라피 기술은 기판 위에 감광성 페이스트를 도포한 후 자외선과 패턴마스크를 사용하는 광식각(photolithography) 방법을 이용하여 세부 패턴을 형성시키는 기술이다, 이 기술은 후막기술로서는 높은 해상도인 선폭
$30{\mu}m$ 이하의 미세도선을 구현할 수 있어, 후막기술을 이용한 고주파 모듈의 제조에 있어서 새로운 대안으로 주목받고 있다. 본 연구에서는 알루미나 기판 상에 수십${\mu}m$ 이하의 마이크로 비아를 가지는 유전체 층을 형성시킬 수 있는 저온소결용 감광성 유전체 페이스트를 개발하였다. 저온소결용 유전체 파우더와 폴리머, 모노머, 광개시제 등의 양을 조절하여 마이크로 비아를 형성할 수 있는 최적 페이스트 조성을 연구하였으며, 노광량 및 현상시간과 같은 공정변수가 마이크로 비아의 해상도에 미치는 영향을 평가하였다. 알루미나 기판에 전면 프린팅 한 후 건조, 노광, 현상, 소성 과정을 거쳐 소결전$37{\mu}m$ , 소결후$49{\mu}m$ 의 해상도를 가지는 마이크로 비아를 형성할 수 있었다. -
저온동시소성 세라믹으로 제작된 모듈을 고주파 대역에 적용할 경우 dimension의 오차는 모듈 특성의 오차를 유발시킨다. Constrained sintering 기술은 XY 방향의 수축을 억제시킴으로써 세라믹 소결체의 dimensional tolerance를 향상시키기 위하여 개발된 기술이다. LTCC의 소성온도에서는 수축하지 않는 비소성층을 LTCC 적층체의 위 아래에 함께 적층시킴으로써 XY 방향의 수축은 기계적으로 억제되며, 두께 방향으로만 수축이 일어난다. 본 연구에서는 LTCC 기판을 constrained sintering 방법으로 소성하고, 그 특성값을 일반적인 소성방법으로 제작하였을 때와 비교하였다. 알루미나 테잎의 제조조건 빛 적층조건을 변화시켜 이에 따른 면수축 제어 특성의 변화를 고찰하였다. 실험결과 알루미나 테잎의 고형분 용량과 부착층의 두께가 면수축 제어를 위하여 고려되어야할 주요 인자임을 확인할 수 있었다.
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The microwave dielectric properties of
$0.7Mg_4Ta_2O_9-0.3TiO_2$ ceramics were investigated. All samples were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature by X-ray Diffractor meter. According to. the X-ray diffraction patterns of the$0.7Mg_4Ta_2O_9-0.3TiO_2$ ceramics, major phase of the hexagonal$Mg_4Ta_2O_9$ were appeared. In the case of$0.7Mg_4Ta_2O_9-0.3TiO_2$ ceramics sintered at$1400^{\circ}C$ , dielectric constant, quality factor and temperature coefficient of resonant frequency were 11.72, 126,419GHz,$-31.82ppm/^{\circ}C$ , respectively. -
This study presents the combined effect of electric field application and mechanical compressive stress loading on deformation in a multilayer ceramic actuator, designed with stacking alternatively
$0.2(PbMn_{1/3}Nb_{2/3}O_3)-0.8(PbZr_{0.475}Ti_{0.525}O_3)$ ceramics and Ag-Pd electrode. The deformation behaviors were thought to be attributed to relative$180^{\circ}$ domain quantities which is determined by pre-loaded stress and electric field. The non-linearity of piezoelectricity and strain are dependent upon the young's modulus resulting from the domain reorientation. -
In this study, the structural, dielectric and piezielectric properities of
$xPb(Mg_{1/3}Nb_{2/3})O_3-(0.5-x)Pb(Ni_{1/3}Nb_{2/3})O_3-0.5Pb(Zr_{0.3}Ti_{0.7})O_3$ ceramics were investigated with the substitution of$PbMg_{1/3}Nb_{2/3}O_3$ . The results showed that the substitution of the$PbMg_{1/3}Nb_{2/3}O_3$ was effective in increasing the dielectric constant and electromechanical coupling factor$(K_p)$ . The dielectric constant, dielectric loss and Kp showed the highest values of 4293, 2.4%, 0.59 relatively, when the substitution of amount of$PbMg_{1/3}Nb_{2/3}O_3$ was 5 mol%. -
In this paper, a disk-type piezoelectric transformer for the high power was investigated with the variation of road resistance. The diameter and thickness of a disk-type piezoelectric transformer was 45mm and 4mm, respectively. The piezoelectric ceramics was composed to PZT-PMN-PSN. The ratio of driving electrode and generating electrode is 2:1. The poling direction of driving part and generating part are the same. A voltage step-up ratio increased with increasing the load resistance,
$R_L$ , so it reached 60 under no road resistance. Also, the maximum efficiency of 97% was obtained. -
Study on the effect of the characteristics of conductor and dielectric material on that of resonatorIn RF application of resonator, cylinerical and transmission line(TRL) type are used generally, especially in ceramic modules the latter is used widely, TRL type resonators are used in VCO and RF filters etc.. TRL type resonators are divided stripline and microstripline and their characteristics depend on that of conductor and dielectric materials. In this study, the effect of material properties on the stripline resonator is measured and analyzed. Besides, the optimum design rule of resonator is presented.
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Nowadays, the study on the ceramic components and modules using LTCC is being performed and on the passives included in modules is being done also. But the characteristics of passives changes in ceramic module due to the coupling between patterns, so each block in module must be analyzed in the state of module including coupling factors. In our research each block of VCO, resonator part, oscillator part, output part is measured and analyzed and that allows the prediction of behavior of VCO.
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본 논문에서는 한쪽이 단락된 스트립선로(Stripline)와 Loading 캐패시턴스(Capacitance)로 구성된 새로운 형태의 1/4파장 스트립선로 공진기를 제안하였으며, 이 공진기를 이용해서 5.2 GHz 대역 무선 LAN용 적층 대역통과 여파기를 설계, 제작 하였다. 제안한 공진기의 전파지연효과(Slow-wave Effect) 때문에, 기존의 공진기에 비해서 길이가 축소되며, 기준 공진주파수(Fundamental Resonant Frequency)에 대한, 첫 번째 기생공진주파수(First Spurious Resonant Frequency) 값이 커지기 때문에, 넓은 상향저지대역(Wide Upper Stopband)을 갖는 초소형의 대역통과 여파기의 설계가 가능하다. 설계한 여파기를 LTCC 적층 공정 기술을 이용하여 제작하였으며 그 크기는
$3.2mm{\times}1.6mm{\times}0.8mm$ 이다. -
Effects of
$CaF_2$ addition as a filler on the high frequency dielectric properties and sintering of CaO-$Al_2O_3-SiO_2-B_2O_3$ (CASB) and ZnO-MgO-$B_2O_3-SiO_2$ (ZMBS) glass composites were investigated. The optimal glass composition in the CASB system was 33.0CaO-$17.0Al_2O_3-35.0SiO_2-15.0B_O_3$ (in wt%). The corresponding dielectric properties were k=8.1 and$Q{\times}fo$ =1,200GHz. The sintering temperature was$800{\mu}m$ . In case of 2MBS system, 25.0ZnO-25.0MgO-20.0$B_2O_3-30.0SiO_2$ (in wt%) glass showed k=6.8 and$Q{\times}fo$ =5,200GHz when it was sintered at$750^{\circ}C$ . The maximum amount of$CaF_2$ in the CASB and 2MBS glass system without any detrimental effect on the sintering was 25.0 v/o and 15.0 v/o, respectively. The addition of$CaF_2$ in the glass systems improved the high frequency dielectric properties. In case of CASB+$CaF_2$ composite, k was 7.1 and$Q{\times}fo$ was 2,300GHz. And in case of 2MBS+$CaF_2$ composite, k was 5.9 and$Q{\times}fo$ was 8,100GHz.$CaF_2$ addition also reduced sintering temperature. Effects of$CaF_2$ on the dielectric and sintering properties was analyzed in terms of viscosity and crystallization behavior changes due to the interaction between$CaF_2$ and the glass systems. -
We investigated the effects of calcination temperature and sintering additives on the sintering behaviors and microwave dielectric properties of
$(Zn_{0.8}Mg_{0.2})TiO_3$ . Highly densified samples were obtained at the sintering temperatures below$1000^{\circ}C$ with additions of 0.45 wt.%$Bi_2O_3$ and 0.55 wt.%$V_2O_5$ . From the examination of the existing phases and microstructures before and after sintering of$(Zn_{0.8}Mg_{0.2})TiO_3$ system calcined at the various temperatures ranging from$800^{\circ}C$ to$1000^{\circ}C$ , it was found that high$Q{\times}f_o$ values were obtained when unreacted or second phases in calcined body were reduced. When calcined at$1000^{\circ}C$ and sintered at$900^{\circ}C$ , it consists of hexagonal as a main phase with uniform microstructure and exhibits$Q{\times}f_o$ value of 42,000 GHz and dielectric constant of 22. -
Sol-gel processing of
$BaTiO_3$ ceramics doped with La(0.01~1.00 at.%) were prepared from metal barium, titanium n-butoxide and lanthanum iso-propoxide. Characterization of the sol-gel-derived powder using XRD, SEM is also reported. The obtained results showed that insulator to semiconductor transition for highly donor-doped barium titanate was closely related to the incorporation of donor into the grains and to the resultant grain size, which were significantly affected by the sinterability of$BaTiO_3$ powders and sintering conditions used. -
The circuit substrate was made from the Low Temperature Cofired Ceramics(LTCC) that a
$\varepsilon_\gamma$ was 7.8. Accumulated Varactor and the low noise transistor which were a Surface Mount Device-type element on LTCC substrate. Let passive element composed R, L, C with strip-line of three dimension in the multilayer substrate circuit inside, and one structure accumulate band-pass filter, resonator, a bias line, a matching circuit, and made it. Used Screen-Print process, and made Strip-line resonator. A design produced and multilayer-type VCO(Voltage Controlled Oscillator), and recognized a characteristic with the Spectrum Analyzer which was measurement equipment. Measured multilayer structure VCO is oscillation frequency 1292[MHz], oscillation output -28.38[dBm], hamonics characteristic -45[dBc] in control voltage 1.5[V], A phase noise is -68.22[dBc/Hz] in 100 KHz offset frequency. The oscillation frequency variable characteristic showed 30[MHz/V] characteristic, and consumption electric current is approximately 10[mA]. -
The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system BaO-ZnO-
$B_2O_3-V_2O_5$ . DTA, XRD and SEM were used to study and characterize BaO-ZnO-$B_2O_3-V_2O_5$ glasses. PbO free paste developed at this paper has thermal expansion of$74{\times}10^{-7}/^{\circ}C$ , DTA transformation point of$460^{\circ}C$ , and firing condition of$560^{\circ}C$ , 10min. -
The battery industries have been developed to the implementation of lithium ion secondary cell from the cell of Ni/Cd and Ni/MH in the past to be asked of an age of high technology from low technology. Also in resent the polymeric cell to get a good high function with an age of new advanced information system is changed from the 21 century to the secondary batteries society. The properties of lithium secondary batteries have the high energy density, the long cycle time, the low self discharge area and the high active voltage. The wanted properties of secondary batteries for the motion of an apparatuses of industries of an high skill age have a small type trend of the energy density and it is become with a strong asking of the industrial society market about the storable medium of the convenience and new power energy. The electrochemical properties is researched for the cell to be synthesised and crystallized the positive active material LiMnO2 of the secondary cell at 9250C to get a new improved data of the electric discharge for that the capacitance of the LiMnO2 thin film that is improving and researching with the properties and a merit and demerit in the this kind of asking.