• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.131-131
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• 2000

We witnessed the enhancement of mangetoresistance (MR) in La0.75Ca0.25MnO3 thin films grown on Si (100) substrates by RF magnetron sputtering. The films are polycrystalline with (100) and (110) orientations. The lattice constants of films are reduced as much as 0.9% compared to the one of the bulk sample, which proves that the compressive stress on films was imposed by Si sbustrate. It is found that the MR value (Δ$\rho$/$\rho$0) of films are 0.33, 0.29 and 0.27 under a magnetic field of 1.5T for each films with deposition temperature of $700^{\circ}C$, 75$0^{\circ}C$ and 80$0^{\circ}C$, respectively. The correlation between the MR values and lattice constants of films is discussed. It is concluded that the compressive stress on films cause the enhancement of MR values of thin films grown on Si (1000 substrates. Some mechanism of compressive stress induced by Si substrate is suggested.

• 마이크로전자및패키징학회지
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• 제6권4호
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• pp.35-39
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• 1999

The $Li_2O-MgO-MgF_2-SiO_2$glasses with addition of $B_2O_3$ were investigated in order to make glass-ceramics for low temperature firing substrate. Glasses were made by melting at $1450^{\circ}C$ in the electronic furnace and crystallized at $750^{\circ}C$. The crystal phases were polycrystalline of lithium boron fluorphlogopite and lithium fluorhectorite. The crystal shape was chanced to granule type from needle type with increasing $B_2O_3$ content. Average particle size of the glass-ceramics after water swelling was 3.77$\mu\textrm{m}$. The optimum sintering temperature and sintering shrinkage of the substrate were $900^{\circ}C$ and 13.4%, respectively.

• 한국세라믹학회지
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• 제44권8호
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• pp.403-406
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• 2007

Ferroelectric Ce-doped $Bi_4Ti_3O_{12}$ (BCT) thin films were deposited by liquid delivery metal organic chemical vapor deposition (MOCVD) onto a $Pt(111)/Ti/SiO_2/Si(100)$ substrate. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the crystal structure, the surface, and the cross-section morphology of the deposited ferroelectric flims. After annealing above $640^{\circ}C$, the BCT films exhibited a polycrystalline structure with preferred (001) and (117) orientations. The BCT lam capacitor with a top Pt electrode showed a large remnant polarization ($2P_r$) of $44.56{\mu}C/cm^2$ at an applied voltage of 5 V and exhibited fatigue-free behavior up to $1.0{\times}10^{11}$ switching cycles at a frequency of 1 MHz. This study clearly reveals that BCT thin film has potential for application in non-volatile ferroelectric random access memories and dynamic random access memories.

• 한국결정성장학회지
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• 제4권3호
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• pp.238-244
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• 1994

보로실리케이트 유리기판과 석영기판을 사용하여 $800^{\circ}C~520^{\circ}C$의 온도 범위에서 용액 성장법에 의한 다결정 실리콘 박막의 성장에 관해 조사 하였다. 기판상에는 용애과의 젖음성을 좋게 해주기 위해 박막의 알루미늄츠오가 실리콘층이 증착되었으며, 용매로는 알루미늄과 실리콘옥사이드와의 반응에 의해서 일어난다. 결정립 크기가 수백 마이크론까지 이르는 실리콘을 얻을 수 있었으며, 석영기 판의 경우에는 보르실리 케이트 유리기판보다 강한 (111) 우선 성장 방향을 보여주고 있다.

• 한국진공학회지
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• 제17권2호
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• pp.130-137
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• 2008

$La_{0.7}Sr_{0.3}MnO_3$ 박막을 rf 마그네트론 스퍼터를 이용하여 챔버 내 산소가스유량비를 0, 40, 80 sccm 으로 조절하고 후열처리 공정 없이 기판온도를 $350^{\circ}C$로 유지하면서 $SiO_2$/Si(100) 및 Si(100) 기판에 증착하였다. 증착된 $La_{0.7}Sr_{0.3}MnO_3$ 박막은 $SiO_2$/Si(100), Si(100) 기판 모두 (100), (110), (200)면을 갖는 polycrystalline 상태였으며, oxygen flow rate이 증가함에 따라 박막의 grain size가 증가하였다. 증가되는 grain size로 인하여 grain boundary가 감소하였고 따라서 높은 oxygen flow rate에서 증착된 박막은 면저항이 감소하는 현상을 나타내었다. $SiO_2$/Si 기판과 Si 기판에 증착된 LSMO 박막의 TCR 값은 약 -2.0 $\sim$ -2.2%를 나타내었다.

• 한국전기전자재료학회논문지
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• 제15권6호
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• pp.486-491
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• 2002

We have fabricated $Bi_{3.25}La_{0.75}Ti_3O_12$ (BLT) thin films on the Pt/Ti/$SiO_2$/Si substrates using a metalorganic decomposition (MOD) method with annealing temperature from $550^{\circ}C$ to $750^{\circ}C$. The structural properties of BLT films examined by x-ray diffraction (XRD). From XRD analysis. BLT thin films show polycrystalline structure. The layered-perovskite phase was obtained by spin-on films at above $600^{\circ}C$ for 1h. Scanning electron microscopy (SEM) showed uniform surface composed of rodlike grains. The grain size of BLT films increased with increasing annealing temperature. The BLT film annealed at $650^{\circ}C$ was measured to have a dielectric constant of 279, dielectric loss of 1.85(%), remanent polarization of $25.66\mu C/\textrm{cm}^2$, and coercive field of 84.75 kV/cm. The BLT thin films showed little polarization fatigue test up to $3.5{\times}10^9$ bipolar cycling at 5 V and 100 kHz.

• 전기학회논문지
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• 제61권9호
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• pp.1296-1299
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• 2012

$YBa_2Cu_3O_{7-x}$ thin films were fabricated by the spin-coating method on $SiO_2$/Si substrate using an alkoxide-based sol-gel method. The structural and electrical properties were investigated for various 1st annealing temperature. Due to the formation of the polycrystalline single phase, synthesis temperature was observed at around $720^{\circ}C-800^{\circ}C$. $YBa_2Cu_3O_{7-x}$ thin films with the 1st annealing temperature of $450^{\circ}C{\sim}500^{\circ}C$ showed the single XRD patterns without the second phase, such as $YBa_2Cu_4O_8$. The thickness of films was approximately $0.23{\mu}m{\sim}0.27{\mu}m$. Aerage grain size, resistance and temperature coefficient of resistance (TCR) of $YBa_2Cu_3O_{7-x}$ thin films with the 1st annealing temperature of $500^{\circ}C$ were $0.27{\mu}m$, $59.7M{\Omega}$ and -3.7 %/K, respecvitely.

• Transactions on Electrical and Electronic Materials
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• 제1권1호
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• pp.22-25
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• 2000

Polycrystalline SBTN layered ferroelectric thin film with various Nb mole ratios were prepared by sol-gel method Pt/ $SiO_2$/Si (100) substrates. The films were annealed at different temperature and characterized in terms of phase and microstructure. The films were crystallized with a high (105) diffraction intensity and had rodike structure, SBTN films fired at 800$^{circ}C$ revealed standard hysteresis loops with no fatigue for up to 10$^{10}$ cycles. At an applied voltage of 5V the dielectric constant($varepsilon$) , dissipation factor (tan $delta$), remanent polarization(ZPr) and coercive field(Ec) of typical S $r_{0.8}$B $i_{2.3}$(T $a_{1-x}$ N $b_{x}$) $O_{9+}$$alpha$/ thin film(x=0.1) prepared on Pt/ $SiO_2$/Si (100) were about 277.7, 0.042, 3.74$mu$C/$textrm{cm}^2$, and 24.8kv/cm respectively.ly.y. respectively.ly.y.y..

• Current Photovoltaic Research
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• 제1권2호
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• pp.103-108
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• 2013

Epitaxial growth of a high-quality thin Si film is essential for the application to low-cost thin-film Si solar cells. A polycrystalline Si film was grown on a $SiO_2$ substrate at $450^{\circ}C$ by a Al-assisted crystal growth process. For the purpose, a thin Al layer was deposited on the $SiO_2$ substrate for Al-assisted crystal growth. However, the epitaxial growth of Si film resulted in a rough surface with humps. Then, we introduced a thin amorphous Si seed layer on the Al film to minimize the initial roughness of Si film. With the help of the Si seed layer, the surface of the epitaxial Si film was smooth and the crystallinity of the Si film was much improved. The grain size of the $1.5-{\mu}m$-thick Si film was as large as 1 mm. The Al content in the Si film was 3.7% and the hole concentration was estimated to be $3{\times}10^{17}/cm^3$, which was one order of magnitude higher than desirable value for Si base layer. The results suggest that Al-doped Si layer could be use as a seed layer for additional epitaxial growth of intrinsic or boron-doped Si layer because the Al-doped Si layer has large grains.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.244-247
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• 1999

The(Sr$\sub$0.85/Ca$\sub$0.15/) TiO$_3$(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/SiO$_2$/Si) using RF sputtering method. The composition of SCT thin films deposited on Si substrate at room temperature is close to stoichiometry(1.102 in A/B ratio). Also, SCT thin films deposited on Pt-coated electrodes have the cubic perovskite structure and polycrystalline state. The maximum dielectric constant of SCT thin films is obtained by annealing at 600[$^{\circ}C$].The dielectric constant changes almost linearly in temperature ranges of -80~+90[$^{\circ}C$].