• Title/Summary/Keyword: pulsed-laser deposition

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Electrical Properties Of MgTiO$_3$ thin films grown by pulsedd laser deposition method (펄스 레이저 증착법으로 증착된 $MgTiO_3$박막의 전기적 특성 분석)

  • 안순홍;노용한;이영훈;강신충;이재찬
    • Journal of the Korean Vacuum Society
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    • v.9 no.3
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    • pp.249-253
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    • 2000
  • We have analyzed electrical characteristics of the amorphous $MgTiO_3$thin films deposited by pulsed laser deposition (PLD) technique with the temperature of 400~$500^{\circ}C$. The electrical characteristics of $MgTiO_3$films heavily depend on the deposition temperature. We speculate that the density of anomalous positive charge (APC) substantially increases as the deposition temperature lowers, causing the HF C-V curves shift to the direction of the negative gate voltage. We further observed that both the degree of C-V shift as a function of the deposition temperature and the density of APC were minimized by the use of $SiO_2$with thickness of approximately 100 $\AA$ between $MgTiO_3$films and the Si substrate.

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Effect of deposition temperature on the photoluminescence of Si nanocrystallites thin films (증착 온도에 따른 실리콘 나노결정 박막의 광학적 특성변화 연구)

  • Jeon, Kyung-Ah;Kim, Jong-Hoon;Choi, Jin-Back;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.04b
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    • pp.38-41
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    • 2002
  • The variation of photoluminescence(PL) properties of Si thin films was investigated by changing deposition temperatures, Si-rich silicon oxide films on p-type (100) Si substrate have been fabricated by pulsed laser deposition(PLD) technique using a Nd:YAG laser. During deposition, the substrates were kept at the temperature range of room temperature(RT) to $400^{\circ}C$. After deposition, samples were annealed at $800^{\circ}C$ in nitrogen ambient, Strong Blue PL has been observed on RT-deposited Si nanocrystallites. When the deposition temperature was increased over $100^{\circ}C$, PL intensities abruptly decreased. The experimental results show the growing mechanism of Si nanocrystallites by PLD.

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Effect of deposition pressure on the morphology of TiO2 nanoparticles deposited on Al2O3 powders by pulsed laser deposition (펄스레이저 증착법에 의한 Al2O3 입자 표면 위 TiO2 나노입자의 코팅)

  • Choi, Bong Geun;Kim, So Yeon;Park, Cheol Woo;Park, Jae Hwa;Hong, Yoon Pyo;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.4
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    • pp.167-172
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    • 2013
  • Titanium dioxides nanoparticles coated aluminum oxide powders were fabricated by pulsed laser deposition (PLD) with Nd : YAG laser at 266 nm. The Pulse laser energy is 100 mJ/pulse. During the irradiation of the focused laser on the $TiO_2$ target, Ar gas is supplied into the chamber. The gas pressure is varied in a range of $1{\times}10^{-2}$ to 100 Pa. Titanium dioxides nanoparticles deposited aluminum oxide powders were characterized by using energy dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscopy (HR-TEM), in order to understand the effect of Ar background gas on surface morphology and properties of the powders. The coated $TiO_2$ nanoparticles had nanosized spherical shape and the crystallite sizes of 10~30 nm. The morphology of coated $TiO_2$ nanoparticles is not affected by gas pressure. However, the particle size and crystallinity slightly increased with the increase of gas pressure. According to this technique, the size and crystallinity of nanoparticles can be easily controlled by controlling pressure during the laser irradiation.

Characteristics of HfO2-Al2O3 Gate insulator films for thin Film Transistors by Pulsed Laser Deposition

  • Hwang, Jae Won;Song, Sang Woo;Jo, Mansik;Han, Kwang-hee;Kim, Dong woo;Moon, Byung Moo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.304.2-304.2
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    • 2016
  • Hafnium oxide-aluminum oxide (HfO2-Al2O3) dielectric films have been fabricated by Pulsed Laser Deposition (PLD), and their properties are studied in comparison with HfO2 films. As a gate dielectric of the TFT, in spite of its high dielectric constant, HfO2 has a small energy band gap and microcrystalline structure with rough surface characteristics. When fabricated by the device, it has the drawback of generating a high leakage current. In this study, the HfAlO films was obtained by Pulsed Laser Deposition with HfO2-Al2O3 target(chemical composition of (HfO2)86wt%(Al2O3)14wt%). The characteristics of the thin Film have been investigated by x-ray diffraction (XRD), atomic force microscopy (AFM) and spectroscopic ellipsometer (SE) analyses. The X-ray diffraction studies confirmed that the HfAlO has amorphous structure. The RMS value can be compared to the surface roughness via AFM analysis, it showed HfAlO thin Film has more lower properties than HfO2. The energy band gap (Eg) deduced by spectroscopic ellipsometer was increased. HfAlO films was expected to improved the interface quality between channel and gate insulator. Apply to an oxide thin Film Transistors, HfAlO may help improve the properties of device.

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Properties of Indium Zinc Oxide Thin Films Prepared by Pulsed Laser Deposition (펄스레이저증착법으로 증착한 Indium Zinc Oxide 박막의 물성)

  • Choi, Hak-Soon;Jeong, Il-Kyo;Shin, Mun-Soo;Kim, Heon-Oh;Kim, Yong-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.7
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    • pp.537-542
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    • 2011
  • Recently, n-InZnO/p-CuO oxide diode has attracted great attention due to possible application for selector device of 3-dimensional cross-point resistive memory structures. To investigate the detailed properties of InZnO (IZO), we have deposited IZO films on the fused quartz substrate using PLD (pulsed laser deposition) method at oxygen pressure of 1~100 mTorr and substrate temperature of RT$\sim600^{\circ}C$. The influence of oxygen pressure and substrate temperature on structural, optical and electrical of IZO films is analyzed using XRD (x-ray diffraction), SEM (scanning electron microscopy), UV-Vis spectrophotometry, spectroscopic ellipsometry (SE) and hall measurements. The XRD results shows that the deposited thin films are polycrystalline over $300^{\circ}C$ of substrate temperature independent of oxygen pressure. The resistivity of films was increased as oxygen pressure and substrate temperature decrease. The thickness and optical constants of the deposited films measured with UV-Vis spectrophotometer were also compared with those of broken SEM and SE results.

Luminescence Characteristics of Y2-xGdxO3:Eu3+ Thin film Grown by Pulsed Laser Ablation (PLD 방법으로 Si(100) 기판위에 증착한 Y2-xGdxO3:Eu3+/ 박막의 형광특성)

  • 이성수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.1
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    • pp.112-117
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    • 2004
  • $Y_2$$_{-x}$G $d_{x}$ $O_3$:E $u^{3+}$(x=0.0, 0.3, 0.6, 1.0, 1.4) luminescent thin films have been grown on Si (100) substrates using pulsed laser deposition. The films grown under different deposition conditions have been characterized using microstructural and luminescent measurements. The crystallinity, the surface morphology and photoluminescence (PL) of the films are highly dependent on the amount of Gd. The photoluminescence (PL) brightness data obtained from $Y_2$$_{-x}$G $d_{x}$ $O_3$:E $u^{3+}$ films grown under optimized conditions have indicated that Si (100) is one of promised substrates for the growth of high quality $Y_2$$_{-x}$G $d_{x}$ $O_3$:E $u^{3+}$ thin film red phosphor. In particular, the incorporation of Gd into $Y_2$ $O_3$ lattice could induce a remarkable increase of PL. The highest emission intensity was observed with $Y_{1.35}$G $d_{0.60}$ $O_3$: $E^{3+}$, whose brightness was increased by a factor of 1.95 in comparison with that of $Y_2$ $O_3$:E $u^{3+}$ films.3+/ films.films.lms.