• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.53-57
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• 2019

In this study, we prepared sputtering cathode for large sputtering thin film in the facing targets sputtering(FTS) system. Before fabrication of cathode equipment, we investigated optimal magnetic flux in the sputtering cathode by using magnetic field stimulation(Comsol). According to the result of magnetic field stimulation, we manufactured the cathode. After we mounted laboratory-designed cathode on FTS system, the discharge properties were observed in vacuum condition. In addition, ITO films were deposited on glass substrate and their electrical and optical properties were investigated by various measurements (four-point probe, UV-VIS spectrometer, field emission scanning electron microscopy(FE-SEM), Hall-effect measurement).

• Journal of the Korean Ceramic Society
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• v.16 no.4
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• pp.213-224
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• 1979

The present work was undertaken: (1) to determine if CaO-partially stabilized $ZrO_2$ prepared by Hot Petroleum Drying Method would show better ionic conductor as an oxygen sensor in molten metals than that prepared by Oxide Wet Mixing Method and than CaO-fully stabilized $ZrO_2$, and (2) to understand the nature of conduction mechanism of CaO-partially stabilized $ZrO_2$ by a comparison of measured electrical conductivity data with theory on defect structure of pure monoclinic $ZrO_2$ and fully stabilized cubic $ZrO_2$. The DC electrical conductivity was measured by 3-probe technique and the AC electrical conductivity by 2-probe technique as a function of temperature in the range 973-1373 K and oxygen partial pressure in the range 10-1-10-25Mpa. The results of the experiments were as follows: 1. CaO-partially stabilized $ZrO_2$ prepared by Hot petroleum Drying Method showed at T=1094-1285 K and $Po_2$=10-7-10-25 MPa a nearly ionic conduction with 4 times higher conductivity than that prepared by Oxide Wet Mixing Method. 2. High-oxygen pressure conductivity tends toward a Po_2^{+1/5}-Po_2^{+1/6}$dependence. An analysis of possible defect structures suggests that CaO-partially stabilized $ZrO_2$ has an anti-Frenkel defect in which singly or doubly ionized oxygen interstitials and defect electrons predominate at T=1094-1285 K and $Po_2$=10-1-10-7MPa. 3. The activation energy for pure electron hole-conduction and ionic conduction of CaO-partially stabilized $ZrO_2$ was found to be 130 KJ/mol at T=973-1373 K, $Po_2$=2, 127 10-2 MPa(air) and 153KJ/mol at T=1094-1285 K respectively.

• Journal of the Korean Vacuum Society
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• v.10 no.4
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• pp.396-402
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• 2001

MgO thin films with 1000 $\AA$ thickness were deposited on Cu substrates by using an electron gun evaporator at room temperature. A 1000 $\AA$ thick Al layer was deposited on the MgO for removing the charging effect of the MgO thin film during the measurements of the sputtering yields. A Ga ion liquid metal was used as the focused ion beam(FIB) source. The ion beam was focused by using double einzel lenses, and a deflector was employed to scan the ion beams into the MgO layer. Both currents of the secondary particle and the probe ion beam were measured, and they dramatically changed with varying the applied acceleration voltage of the source. The sputtering yield of the MgO layer was determined using the values of the analyzed probe current, the secondary particle current, and the net current. When the acceleration voltage of the FIB system was 15 kV, the sputtering yield of the MgO thin film was 0.30. The sputtering yield of the MgO thin film linearly increases with the acceleration voltage. These results indicate that the FIB system is promising for the measurements of the sputtering yield of the MgO thin film.

• Korean Journal of Materials Research
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• v.13 no.1
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• pp.43-47
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• 2003

As and BF$_2$dopants are implanted for the formation of source/drain with dose of 1${\times}$10$^{15}$ ions/$\textrm{cm}^2$∼5${\times}$10$^{15}$ ions/$\textrm{cm}^2$ then formed cobalt disilicide with Co/Ti deposition and doubly rapid thermal annealing. Appropriate ion implantation and cobalt salicide process are employed to meet the sub-0.13 $\mu\textrm{m}$ CMOS devices. We investigated the process results of sheet resistance, dopant redistribution, and surface-interface microstructure with a four-point probe, a secondary ion mass spectroscope(SIMS), a scanning probe microscope (SPM), and a cross sectional transmission electron microscope(TEM), respectively. Sheet resistance increased to 8%∼12% as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{V}$ , while sheet resistance uniformity showed very little variation. SIMS depth profiling revealed that the diffusion of As and B was enhanced as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{＋}$ . The surface roughness of root mean square(RMS) values measured by a SPM decreased as dose increased in $CoSi_2$$n^{＋}$ , while little variation was observed in $CoSi_2$$p^{＋}$ . Cross sectional TEM images showed that the spikes of 30 nm∼50 nm-depth were formed at the interfaces of $CoSi_2$$n^{＋}$ / and $CoSi_2$/$p^{＋}$, which indicate the possible leakage current source. Our result implied that Co/Ti cobalt salicide was compatible with high dose sub-0.13$\mu\textrm{m}$ process.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.449-449
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• 2013

최근 반도체 소자의 집적회로는 점점 복잡해지고 있는 반면, 소자의 크기는 작아지고 있으며 그로 인해 패드의 크기가 작아지고 패드사이의 간격 또한 협소해지고 있다. 따라서 웨이퍼 단계에서 제조된 집적회로의 불량여부를 판단하기위한 검사 장비인 프로브카드(Probe Card)의 높은 집적도가 요구되고 있다. 하지만 기존의 MEMS 공법으로 제작되는 프로브 빔은 복잡한 제조 공정과 높은 생산비용, 낮은 집적도의 문제점을 가지고 있다. 본 연구에서는 이러한 문제점을 해결하기 위하여 간단한 제조 공정과 낮은 생산비용, 높은 집적도를 가지는 프로브 빔을 개발하기 위하여 절연절단 방식으로 BeCu (Beryllium-Copper) 프로브 빔을 제작하였다. 낮은 소비 전력으로 우수한 프로브 빔 어레이를 제작하기 위해서 가장 고려해야할 대상은 프로브 빔의 재료와 구조(형상)이다. 절연전단 방식으로 프로브 빔을 형성할 때 요구되는 Fusing current는 프로브 빔의 구조(형상)에 크게 영향을 받는다. 낮은 Fusing current는 소비 전력을 줄여주고, 절연절단으로 형성되는 프로브 빔의 단면(끝)을 날카롭게 하여 프로브 빔과 집적회로의 패드 간의 접촉 저항을 감소시킨다. 프로브 빔의 제작은 BeCu 박판을 빔 형태로 식각하여 제작하였으며, 실리콘 비아 홀(Via hole) 구조의 기판위에 정렬하여 soldering 공정을 통해 실리콘 기판과 BeCu 박판을 접합시켰다. 접합된 프로브 빔의 끝부분을 들어 올린 상태로 전류를 인가하여 stress free 상태로 만들어 내부 응력을 제거하였으며, BeCu 박판에 fusing current를 인가하여 BeCu 박판 프레임으로부터 제거를 하였다. 제작된 프로브 빔의 길이는 1.7 mm, 폭은 $50{\mu}m$, 두께는 $15{\mu}m$, 절단부의 단면적은 1$50{\mu}m^2$로 제작되었다. 그리고 프로브 빔의 절단부의 길이는 $50{\mu}m$ 부터 $90{\mu}m$까지 $10{\mu}m$ 증가시켜 제작되었다. 이후에 절연절단 공정에 요구되는 Fusing current를 측정하였고, 절연절단 후의 절단면의 형상을 SEM (Scanning Electron Microscope)장비를 통하여 확인하였다. 절단부의 길이가 $50{\mu}m$일 때 5.98A의 fusing current를 얻었으며, 절연절단 후 절단부 상태 또한 가장 우수했다. 본 연구에서 제안된 프로브 빔 제작 방법은 프로브카드 및 테스트 소켓(Test socket) 생산에 응용이 가능하리라 기대한다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.5
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• pp.567-577
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• 2016

The hutches which are installed in the beamline are largely classified into two, i.e XPP (X-ray pump probe) and CXI (Coherent X-ray image). Laser room is installed on the hutch and provides laser to XPP and CXI simultaneously. And two hutches have heavy crane to install some optics equipments. Safety and reliability of hutch structures should be taken into account for the precise operating of the laser facilities, so vibration analysis is essential to do this. The main purpose of vibration analysis is to install hutch structures with large stiffness. We have changed materials specification several times to install hutch structures having strong stiffness. Now hutch structures were installed and checked vibration status at laser room and XPP hutch. The results of laser table and robot arm satisfy vibration criteria. This paper explains about the design and vibration analysis of hutch structures.

• Journal of the Korean Vacuum Society
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• v.6 no.3
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• pp.287-292
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• 1997

This study was tried to form the silica waveguide using high density plasma. Plasma characteristics have been investigated as a function of etch parameters using a single Langmuir probe and optical emission spectroscopy(OES). As etch parameters, $CF_4/CHF_3$ ratio, bias power, and source power were chosen as main variables. The oxide etch characteristics of inductively coupled plasma(ICP) dry etcher such as the etch rate, etch profile, and surface roughness were investigated s a function of etch parameters. On the basis of these results, the core pattern of the wave guide composed of $SiO_2-P_2O_5$ was formed. It was confirmed that the etch rate of $SiO_2-P_2O_5$ core layer was 380 nm/min and the aluminum selectivity to oxide, that is, mask layer was approximately 30:1. The SEM images showed vertical etched profiles and minimal loss of pattern width.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.2037-2043
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• 2017

The surface protein hemagglutinin (HA) mediates the attachment of influenza virus to host cells containing sialic acid and thus facilitates viral infection. Therefore, HA is considered as a good target for the development of diagnostic tools for influenza virus. Previously, we reported the isolation of single-stranded aptamers that can distinguish influenza subtype H1 from H5. In this study, we describe a method for the selective electrical detection of H1 using the isolated aptamer as a molecular probe. After immobilization of the aptamer on Si wafer, enzyme-linked immunosorbent assay (ELISA) and field emission scanning electron microscopy (FE-SEM) showed that the immobilized aptamer bound specifically to the H1 subtype but not to the H5 subtype. Assessment by cyclic voltammetry (CV) also demonstrated that the immobilized aptamer on the indium thin oxide-coated surface was specifically bound to the H1 subtype only, which was consistent with the ELISA and FE-SEM results. Further measurement of CV using various amounts of H1 subtype provided the detection limit of the immobilized aptamer, which showed that a nanomolar scale of target protein was sufficient to produce the signal. These results indicated that the selected aptamer can be an effective probe for distinguishing the subtypes of influenza viruses by monitoring current changes.

• Journal of the Korean Vacuum Society
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• v.6 no.1
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• pp.91-96
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• 1997

The electrical characteristics and the plasma parameters of planar inductively coupled plasmas (ICP) have been measured. The resistance of the total load including the coil and the plasma varied from 1 to 4 W and the inductance from 1.5 m to 2 mH when the power was changed from 100 to 1000 W and the pressure from 1 to 10 mTorr. The density of electron measured by Langmuir probe was over $10^{11}/\textrm{cm}^3$ and the temperature varied between 3 and 5 eV as the process conditions were changed. Bias modulation was adopted as a new method to improve the selectivity of $SiO_2$on Si in $C_4F_8$ (octafluorocyclobutane) plasma. The selectivity was improved as the duty ratio decreased, but the etch rate of $SiO_2$decreased below 400$\AA$/min. $H_2$addition to $C_4F_8$ plasma showed that the etch selectivity could be higher than 50 and the etch rate of $SiO_2$over 2000$\AA$/min when 60% $H_2$was added.

• Korean Journal of Materials Research
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• v.17 no.2
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• pp.73-80
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• 2007

For the sub-65 nm CMOS process, it is necessary to develop a new silicide material and an accompanying process that allows the silicide to maintain a low sheet resistance and to have an enhanced thermal stability, thus providing for a wider process window. In this study, we have evaluated the property and unit process compatibility of newly proposed composite silicides. We fabricated composite silicide layers on single crystal silicon from $10nm-Ni_{1-x}Co_x/single-crystalline-Si(100),\;10nm-Ni_{1-x}Co_x/poly-crystalline-\;Si(100)$ wafers (x=0.2, 0.5, and 0.8) with the purpose of mimicking the silicides on source and drain actives and gates. Both the film structures were prepared by thermal evaporation and silicidized by rapid thermal annealing (RTA) from $700^{\circ}C\;to\;1100^{\circ}C$ for 40 seconds. The sheet resistance, cross-sectional microstructure, surface composition, were investigated using a four-point probe, a field emission scanning probe microscope, a field ion beam, an X-ray diffractometer, and an Auger electron depth profi1ing spectroscopy, respectively. Finally, our newly proposed composite silicides had a stable resistance up to $1100^{\circ}C$ and maintained it below $20{\Omega}/Sg$., while the conventional NiSi was limited to $700^{\circ}C$. All our results imply that the composite silicide made from NiCo alloy films may be a possible candidate for 65 nm-CMOS devices.