• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2007년 추계학술발표대회 개요집
• /
• pp.282-284
• /
• 2007

The superconductor characteristics of BSCCO spray films by Heat treatment was studied. $Bi_2Sr_2CaCu_2O_x$(Bi-2212) is high-Tc superconductor(HTS) coatings have been prepared by Heat treatment. Where high current carrying capabilities are required and therefore thick film and bulk material are called for, the Bi2Sr2Ca1Cu2O8-d(Bi-2212)compound has evoleved as one of the most promising. and the Bi-2212 HTS coating layer is synthesized through the peritectic reaction between Sr-Ca-Cu oxide coating layer and Bi-Cu oxide coating layer by partial melting process. The superconducting characteristics depends on the spray distance which was related to the spray particle melt. The Bi-2212 HTS layer consists of the whisker growth and secondary phase in 2212 layer were observed.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.81-84
• /
• 2001

The effect of silver oxide (14 wt.%) addition to YBCO compounds and electrophoretic deposition of composite particles prepared by solid phase reaction have been investigated. The results were compared with those for as-processed samples with YBCO films on Ag wire substrate. Our experiments show that the adhesion, microstructure changes, superconducting properties of these films is sensitive to the silver content and sintering conditions. Adding a small amount of PEG tends to remove cracks in the YBCO and (YBCO + Ag) films, which develop during the heating process. An attempt has been made to explain the experimental observations regarding variation of critical current density with the YBCO and (YBCO + Ag) films.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
• /
• pp.806-808
• /
• 2004

본 연구에서는 MEMS 공정에 의해 제작된 실리콘 멤브레인 위에 스크린 프린팅법을 이용하여 압전 후막을 제작, 그 특성을 관찰하였다. 실리콘 웨이퍼의 후면을 각각 다른 4가지의 크기로 식각하여 멤브레인을 제작하였다. 제작된 멤브레인 위에 하부전극 Ag-Pd를 스크린 프린팅법으로 형성하고, 그 위에 압전 후막을 스크린 프린팅하여 열처리 하였다. 제작된 압전 후막위에 MFM(Metal-Ferroelectric-Metal)구조의 액츄에이터를 제작하기위해 상부전극으로 Pt를 스퍼터링으로 증착하였다. 제작된 마이크로 액츄에이터는 SEM(Scanning Electron Microscope)으로 구조분석하고, RT66A와 MTI2000으로 동작특성을 해석 하였다.

• Journal of electromagnetic engineering and science
• /
• 제8권3호
• /
• pp.129-133
• /
• 2008

An integrated passive device(IPD) technology by semi-insulating(SI)-GaAs-based fabrication has been developed to meet the ever increasing needs of size and cost reduction in wireless applications. This technology includes reliable NiCr thin film resistor, thick plated Cu/Au metal process to reduce resistive loss, high breakdown voltage metal-insulator-metal(MIM) capacitor due to a thinner dielectric thickness, lowest parasitic effect by multi air-bridged metal layers, air-bridges for inductor underpass and capacitor pick-up, and low chip cost by only 6 process layers. This paper presents the Wilkinson power divider with excellent performance for digital cellular system(DCS). The insertion loss of this power divider is - 0.43 dB and the port isolation greater than - 22 dB over the entire band. Return loss in input and output ports are - 23.4 dB and - 25.4 dB, respectively. The Wilkinson power divider based on SI-GaAs substrates is designed within die size of $1.42\;mm^2$.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
• /
• pp.169-171
• /
• 1993

In order to estimate space charging process in the corona charging apparatus which has been used to make polymer electret cell, the electrical properties of 30[${\mu}m$] thick polypropylene film were obtained from TSC measurement after corona charging between copper knife electrode and aluminum cylinder electrode with the voltage of -8, -7, -6, -5 (kV). And, the electrostatic contour and the electric field vector were calculated using Finite Element Method with the electrical properties obtained from TSC spectra analysis. The edge effect around the edge of knife electrode affects electrostatic contour on the surface of specimen and the electric field concentration inside the polymer. As a result the uneven charging state in the electret cell due to the mistake of design was calculated, and the optimal design of corona charging apparatus opprobriate to various specimen was come to be practicable.

• 한국정밀공학회지
• /
• 제30권2호
• /
• pp.241-246
• /
• 2013

This paper reports fabrication and characterization of cellulose Electro-Active Paper (EAPap) with increased thickness. Usual thickness of cellulose EAPap was $15{\mu}m$. This thickness needs to be increased to enhance the mechanical force output of EAPap. To fabricate thick cellulose EAPap, the fabrication process parameters including casting and drying processes should be investigated. In this paper, the casting thickness is increased from $800{\mu}m$ to $1500{\mu}m$, and heating times on a hot plate before and after curing process are introduced at 40 and $60^{\circ}C$ for 30 and 60 minutes, respectively. Thickness measurement, Thermal Gravitational Analysis (TGA), UV-transmittance, Young's modulus, and piezoelectric charge constant are measured. Heated EAPaps with increased thickness have similar TGA result, higher transmittance, higher Young's modulus and lower piezoelectric charge constant.

• 대한전자공학회논문지SD
• /
• 제40권7호
• /
• pp.481-485
• /
• 2003

25㎛ 두께의 폴리이미드 박핀 기판을 glass 기판에 부착하여 최대 온도 150℃에서 비정질 실리콘 TFT를 제작하였다. 본 논문은 plastic 기판 위에 TFT가 제작되는 공정 절차를 요약하고 glass 위에 제작된 TFT와 ON/OFF 전달특성과 전계효과 이동도를 서로 비교해 보았다. a-SiN:H 코팅층은 plastic 기판의 표면 거칠기를 감소시키는 중요한 역할을 하여 TFT의 누설전류를 감소시키고 전계효과 이동도를 증가시켰다. 따라서 a-SiN:H 코팅층을 이용하여 plastic 기판에 양철의 TFT를 제작하였다.

• 한국표면공학회지
• /
• 제55권6호
• /
• pp.353-362
• /
• 2022

Recently, transmittance of photomasks for ultra-violet (UV) region is getting more important, as the light source wavelength of an exposure process is shortened due to the demand for technologies about high integration and miniaturization of devices. Meanwhile, such problems can occur as damages or the reduction of yield of photomask as electrostatic damage (ESD) occurs in the weak parts due to the accumulation of static electricity and the electric charge on chromium metal layers which are light shielding layers, caused by the repeated contacts and the peeling off between the photomask and the substrate during the exposure process. Accordingly, there have been studies to improve transmittance and antistatic performance through various functional coatings on the photomask surface. In the present study, we manufactured antireflection films of Nb₂O₅, | SiO₂ structure and antistatic films of ITO designed on 100 × 100 × 3 mmt sodalime glass by DC magnetron sputtering system so that photomask can maintain high transmittance at I-line (365 nm). ITO thin film deposited using In/Sn (10 wt.%) on sodalime glass was optimized to be 10 nm-thick, 3.0 × 103 𝛺/☐ sheet resistance, and about 80% transmittance, which was relatively low transmittance because of the absorption properties of ITO thin film. High average transmittance of 91.45% was obtained from a double side antireflection and antistatic thin films structure of Nb₂O₅ 64 nm | SiO₂ 41 nm | sodalime glass | ITO 10 nm | Nb₂O₅ 64 nm | SiO₂ 41 nm.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.344-344
• /
• 2014

Transparent amorphous oxide semiconductors such as a In-Ga-Zn-O (a-IGZO) have advantages for large area electronic devices; e.g., uniform deposition at a large area, optical transparency, a smooth surface, and large electron mobility >10 cm2/Vs, which is more than an order of magnitude larger than that of hydrogen amorphous silicon (a-Si;H).1) Thin film transistors (TFTs) that employ amorphous oxide semiconductors such as ZnO, In-Ga-Zn-O, or Hf-In-Zn-O (HIZO) are currently subject of intensive study owing to their high potential for application in flat panel displays. The device fabrication process involves a series of thin film deposition and photolithographic patterning steps. In order to minimize contamination, the substrates usually undergo a cleaning procedure using deionized water, before and after the growth of thin films by sputtering methods. The devices structure were fabricated top-contact gate TFTs using the a-IGZO films on the plastic substrates. The channel width and length were 80 and 20 um, respectively. The source and drain electrode regions were defined by photolithography and wet etching process. The electrodes consisting of Ti(15 nm)/Al(120 nm)/Ti(15nm) trilayers were deposited by direct current sputtering. The 30 nm thickness active IGZO layer deposited by rf magnetron sputtering at room temperature. The deposition condition is as follows: a rf power 200 W, a pressure of 5 mtorr, 10% of oxygen [O2/(O2+Ar)=0.1], and room temperature. A 9-nm-thick Al2O3 layer was formed as a first, third gate insulator by ALD deposition. A 290-nm-thick SS6908 organic dielectrics formed as second gate insulator by spin-coating. The schematic structure of the IGZO TFT is top gate contact geometry device structure for typical TFTs fabricated in this study. Drain current (IDS) versus drain-source voltage (VDS) output characteristics curve of a IGZO TFTs fabricated using the 3-layer gate insulator on a plastic substrate and log(IDS)-gate voltage (VG) characteristics for typical IGZO TFTs. The TFTs device has a channel width (W) of $80{\mu}m$ and a channel length (L) of $20{\mu}m$. The IDS-VDS curves showed well-defined transistor characteristics with saturation effects at VG>-10 V and VDS>-20 V for the inkjet printing IGZO device. The carrier charge mobility was determined to be 15.18 cm^2 V-1s-1 with FET threshold voltage of -3 V and on/off current ratio 10^9.

• 센서학회지
• /
• 제11권3호
• /
• pp.155-162
• /
• 2002

CO 기체 감지 특성을 향상시키기 위해서 3 mol% ZnO를 첨가한 $SnO_2$와 3mol% $SnO_2$를 첨가한 ZnO의 적층 형태를 변화시켜 연구하였다. 적층 구조는 단일층, 복층, 그리고 이종층 구조로 후막 인쇄법을 사용하여 제작하였다. $SnO_2$-ZnO계에서 제 2상은 발견되지 않았다. 전도성은 $SnO_2$에 ZnO를 첨가하면 감소하고, ZnO에 $SnO_2$를 첨가하면 증가하였다. 측정 온도증가와 CO 기체 유입으로 전도성은 증가하였다. 단층 및 복층의 후막센서 구조의 감도 향상은 없었으나, $SnO_2$ 3ZnO-ZnO $3SnO_2$/substrate 구조의 이종층 센서의 감도는 향상되었다. 센서 구조에 관계없이 I-V 변화는 모두 직선성을 나타내서 Ohmic 접합 특성을 이루고 있었다.