• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.427-430
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• 2008

BaTiO3 and SrTiO3 thin films were fabricated on Pt/Ti/SiO2/Si substrate by the pulsed laser deposition process. The dependence of the deposited film quality upon the partial oxygen pressure during the deposition process was importantly examined. Regardless of the oxygen pressure, the as-deposited films were not fully crystallized. However, the film deposited at low oxygen pressure became well crystallized after the annealing process. It was concluded, therefore, that the partial oxygen pressure is reduced as low as possible during the deposition process and then anneal the as-deposited samples at ambient pressure to fabricate the well crystallized SrTiO3 and BaTiO3 films by laser ablation.

• 전자공학회논문지D
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• 제35D권7호
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• pp.72-78
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• 1998

This paper is focused on the fabrication of reliable novel antifuse, which could operate at low voltage along with the improvement in OFF and ON-state properties. The fabricated antifuse consists of Al/BaTi$_{2}$O$_{3}$/SiO$_{2}$/TiW-silicide structure. Through the systematic analyses for bottom metal and the intermetallic insulator, material and electri cproperties were investiaged. TiW-silicide as the bottom electrode had smooth surface with average roughness of 11.angs. at 10X10.mu.m$^{2}$ and was bing kept as-deposited SiO$_{2}$ film stable. Amorphous BaTi$_{2}$O$_{3}$ film as the another insulator was chosen because of its low breakdown strength (2.5MV/cm). breakdown voltage of antifuse is remarkably reduced by using BaTi$_{2}$O$_{3}$ film, and leakage current of that maintained low level due to the SiO$_{2}$ film. Low ON-resistance (46.ohm./.mu.m$^{2}$) and low programming voltage(9.1V) can be obtained in theses antifuses with 220.angs. double insulator layer and 19.6X10$^{-6}$ cm$^{2}$ area, while keeping sufficient OFF-state reliability (less than 1nA).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.73-76
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• 2001

We deposited epitaxial $Ba_{0.6}Sr_{0.4}TiO_{3}(BST)$ films having thickness of 400 nm on MgO(001) substrates, where a 10 nm thick $Ba_{1-x}Sr_{x}TiO_{3}$ (x = 0.1 - 0.7) interlayer was inserted between BST and MgO to manipulate the stress of the BST films. Since the main difference of those epitaxial BST films was the lattice constant of the interlayers, we were very successful in controlling the stress of the BST films. BST films under small tensile stress showed larger dielectric constant than that without stress as well as those under compressive stress. Stress relaxation was investigated using epitaxial BST films with various thicknesses grown on different interlayers. For BST films grown on $Ba_{0.7}Sr_{0.3}TiO_{3}$ interlayers, the critical thickness was about 600 nm. On the other hand, the critical thickness of single-layer BST film was less than 100 nm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.73-76
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• 2001

We deposited epitaxial $Ba_{0.6}$S $r_{0.4}$Ti $O_3$(BST) films having thickness of 400 nm on MgO(001) substrates, where a 10 nm thick $Ba_{1-x}$S $r_{x}$Ti $O_3$(x=0.1-0.7) interlayer was inserted between BST and MgO to manipulate the stress of the BST films. Since the main difference of those epitaxial BST films was the lattice constant of the interlayers, we were very successful in controlling the stress of the BST films. BST films under small tensile stress showed larger dielectric constant than that without stress as well as those under compressive stress. Stress relaxation was investigated using epitaxial BST films with various thicknesses grown on different interlayers. For BST films grown on $Ba_{0.7}$S $r_{0.3}$Ti $O_3$ interlayers, the critical thickness was about 600 nm. On the other hand, the critical thickness of single-layer BST film was less than 100 nm.00 nm.m.m.m.

• 한국자기학회지
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• 제11권3호
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• pp.129-133
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• 2001

본 연구에서는 TiO$_2$ 하지층이 첨가된 hexagonal barium-ferrite(BaM) 박막을 RF/DC magnetron sputtering system을 이용하여 상온에서 증착한 후, 여러 온도에서 열처리하여 결정화하였다. BaM박막에 TiO$_2$ 하지층을 첨가하여 열처리한 경우 Si와 BaM의 (006), (106), (114), (217), (2011) peak들이 사라지고 (008)의 intensity가 낮아졌으며 SiO$_2$와 (116), (302)의 peak들이 성장하였음을 XRD pattern을 통하여 알 수 있었다. BaM 박막의 자기적 특성을 VSM을 통하여 알아본 결과, 보자력, 잔류자화, 각형비 등의 자기적인 특성들은 수직에 비해 수평이 더 좋게 나타났는데, 이러한 결과로 박막면에 평행한 방향으로의 자화용이축이 존재하고 있다는 것을 알 수 있었다. SEM을 통하여 증착압력 및 열처리 시간에 따른 결정화 정도와 자기적 특성을 알아본 결과 5 mTor 보다 10 mTrr에서 더 좋게 나타났으며, 열처리를 시작한 뒤 10분 이내에 750 $^{\circ}C$ 이상에서 대부분의 특성변화가 일어났음을 알 수 있었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2000년도 추계학술발표강연 및 논문개요집
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• pp.47-47
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• 2000

• 한국전기전자재료학회논문지
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• 제11권12호
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• pp.1108-1114
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• 1998

$BaTiO_3$ thin films preferred c-axis orientation for the potential application of ferroelectric memory devices were deposited on silicon substrates(100) by RF sputtering and annealed at 800 and 900[$^{\circ}C$] in air. The BT(100)/BT(110) peak ratio of the sputtered sample was decreased with post-annealing in air. According to increasing with annealing temperature and time, the peak ratio of BT(100)/BT(110) was decreased and the surface density of thin film was high. Dielectric characteristics of $BaTiO_3$ thin film was measured as a function of annealing temperature and frequency. The dielectric constants were increased with annealing and decreased with frequency by space charge polarization and dipole polarization below 600[kHz]. The remanent polarization and coercive field in P-E hysteresis loop of $BaTiO_3$thin film were increased with the annealing temperature in air. The remanent polarization and coercive filed annealed at 800[$^{\circ}C$] for 1hr were 1.2[$\mu$C/$cm^2$] and 200[kV/cm]

• E2M - 전기 전자와 첨단 소재
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• 제8권1호
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• pp.77-82
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• 1995

PTCR(Positive Temperature Coefficient of Resistivity) thermistor in thin film BaTiO$_{3}$ system was prepared by using radio frequency(13.56 MHz) and DC magnetron sputter equipment. Polycrystalline, surface structure, and R-T(Resistivity-Temperature) characteristics of the specimens were measured by X-ray diffraction(D-Max3, Rigaku, Japan), SEM(Scanning Electron Microscopy: M.JSM84 01, Japan), and insulation resistance measuring system (Keithley 719), respectively. Thin films characteristics of the thermistor showed different properties depending on the substrate even with the same sputtering condition. The thin film formed on the A1$_{2}$O$_{3}$ substrate showed a good crystalline and a low resistivity at below curie point. However, the thin films prepared on slide glass and Si wafer were amorphous. The thicknesses of the three samples prepared under the same process conditions were 700[.angs.], 637.75[.angs.], and 715[.angs.], respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.301-304
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• 2002

We investigated the structural and electrical properties of Ce-doped Ba($Zr_{0.2}Ti_{0.8}$)$O_3$(BCZT) thin films with a mole fraction of x=0.2 and a thickness about 100 nm. BCZT films were prepared on Pt/Ti/$SiO_2$/Si substrate by a RF magnetron sputtering system. We have measured the thickness profile with Ar/$O_2$ ratio and the surface roughness. It was observed that the oxygen gas, which introduced during the film deposition, have an influence on the roughness of the film and the film roughness was reduced by annealing from 2.33 nm to 2.02 m (RMS at $500^{\circ}C$, Ar:6 scrim, $O_2$:6 sccm). We have found that annealing procedure after top electrode deposit can reduce the dissipation factor.

• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.361-364
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• 2003

It was investigated that the structural and electrical Properties of Ce-doped Ba(Zr$_{x}$Ti$_{1-x}$ )O$_3$ (BCZT) thin films with a mole fraction of x=0.2 and a thickness about 100 nm. BCZT films were prepared on Pt/Ti/SiO$_2$/Si substrate by a RF magnetron sputtering system. We have measured the thickness profile with Ar/O$_2$ ratio and the surface roughness. It was observed that the oxygen gas, which introduced during the film deposition, have an influence on the roughness of the film and the film roughness was reduced by annealing from 2.33 nm to 2.02 nm (RMS at 500 $^{\circ}C$, Ar:6 sccm, $O_2$:6 sccm). It was found that annealing procedure after top electrode deposit can reduce the dissipation factor.