• Title/Summary/Keyword: Pulsed Laser Ablation(PLD)

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Laser Ablation : Fundamentals and applications in Micropatterning and Thin Film Formation

  • J. Heitz;D. Bauerle;E. Arenholz;N. Arnold;J.T. Dickinson
    • Journal of Photoscience
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    • v.6 no.3
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    • pp.103-108
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    • 1999
  • We present recent results on ablation mechanism, single-pulse laser micropatterning , pulsed-laser deposition(PLD) and particulates formation accompanying laser ablation, with special emplasis on polymers, in particular polymide, (PI), and polytetrafluoroethylene, (PTFE). Ablation of polymers is described on the basis of photothermal bond breaking within the bulk material. Here, we assume a first order chemical reaction, which can be described by an Arrhenius law. Ablation starts when the density of broken bonds at the surface reaches a certain critical value. Single-pulse laser ablation of polyimide shows a clear-length dependence of the threshold fluence. This experimental result strongly supports a thermal ablation model. We discuss the various possibilities and drawbacks of PLD and describe the morphology, physical properties and applications of PTFE films.

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Nano Fabrication of Functional Materials by Pulsed Laser Ablation

  • Yun, Jong-Won
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.11a
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    • pp.6.2-6.2
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    • 2009
  • Nanostructured materials arecurrently receiving much attention because of their unique structural andphysical properties. Research has been stimulated by the envisagedapplications for this new class of materials in electronics, optics, catalysisand magnetic storage since the properties derived from nanometer-scalematerials are not present in either isolated molecules or micrometer-scalesolids. This study presents the experimental results derived fromthe various functional materials processed in nano-scale using pulsed laserablation, since those materials exhibit new physical phenomena caused by thereduction dimensionality. This presentation consists of three mainparts to consider in pulsed laser ablation (PLA) technique; first nanocrystallinefilms, second, nanocolloidal particles in liquid, and third, nanocoating fororganic/inorganic hybridization. Firstly, nanocrystalline films weresynthesized by pulsed laser deposition at various Ar gas pressures withoutsubstrate heating and/or post annealing treatments. From the controlof processng parameters, nanocystalline films of complex oxides and non-oxidematerials have been successfully fabricated. The excellentcapability of pulsed laser ablation for reactive deposition and its ability totransfer the original stoichiometry of the bulk target to the deposited filmsmakes it suitable for the fabrication of various functionalmaterials. Then, pulsed laser ablation in liquid has attracted muchattention as a new technique to prepare nanocolloidal particles. Inthis work, we represent a novel synthetic approach to directly producehighly-dispersed fluorescent colloidal nanoparticles using the PLA from ceramicbulk target in liquid phase without any surfactant. Furthermore, novel methodbased on simultaneous motion tracking of several individual nanoparticles isproposed for the convenient determination of nanoparticle sizedistributions. Finally, we report that the GaAs nanocrystals issynthesized successfully on the surface of PMMA (polymethylmethacrylate)microspheres by modified PLD technique using a particle fluidizationunit. The characteristics of the laser deposited GaAs nanocrytalswere then investigated. It should be noted that this is the first successfultrial to apply the PLD process nanocrystals on spherical polymermatrices. The present process is found to be a promising method fororganic/inorganic hybridization.

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Synthesis and characterization of GaN nanoparticles by pulsed laser deposition (펄스레이저증착법에 의한 GaN 나노입자의 합성 및 특성분석)

  • ;;;Koshizaki Naoto
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.13 no.2
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    • pp.79-82
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    • 2003
  • GaN nanoparticles were synthesized by the pulsed laser deposition (PLD) process on $SiO_2$substrate after irradiating the surface of the GaN sintered pellet by the ArF (193 nm) excimer laser. At this moment Ar gas pressure of 100 Pa, 50 Pa, 10 Pa and 1 Pa were applied during the ablation process and laser power of 100 mJ and 200 mJ were also applied. The synthesized fan nanoparticles were characterized by XRD, SEM, TEM, XPS and optical absorption spectra. The synthesized GaN nanoparticles had the crystallite sizes of 20~30 nm, and besides, GaN nanoparticles synthesized under low Ar gas pressure compared to the others corresponded with stoichiometry, and the optical band edge of the GaN nanoparticles was blueshifted.

Laser Ablation of a ZnO:P2O5 Target under the Presence of a Transverse Magnetic Field

  • Alauddin, Md.;Park, Jin-Jae;Gwak, Doc-Yong;Song, Jae-Kyu;Park, Seung-Min
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.798-802
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    • 2010
  • From time-resolved optical emission spectra, we have investigated the effects of a transverse magnetic field on the expansion of a plasma plume produced by laser ablation of a ZnO:$P_2O_5$ ceramic target in oxygen active atmosphere. The emission spectra of $Zn^{+*}$, $P^{+*}$, and $Zn^*$ neutrals in the presence of magnetic field turn out to be considerably different from those without magnetic field. The characteristics of the deposited films grown on amorphous fused silica substrates by pulsed laser deposition (PLD) are examined by analyzing their photoluminescence (PL), X-ray diffraction (XRD), and UV-visible spectra.

ZnO Nanowires Fabricated by Pulsed Laser Deposition using Gold Catalyst (PLD-Furnace로 증착시킨 금촉매를 이용한 ZnO 나노와이어 합성)

  • Son, Hyo-Jeong;Jeon, Kyung-Ah;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.5-6
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    • 2005
  • ZnO nanowlres (NWs) were fabricated using Au as catalyst for a method combining laser ablation cluster formation and vapor-liquid-solid (VLS) growth. The target used in synthesis was pure ZnO ceramics. Two different substrates were used; (0001)-oriented sapphires and Au-coated sapphires. The Au thin film was deposited by thermal evaporation and the thickness was about 50 ${\AA}$. ZnO NWs were only formed in case of that used catalyst metal. Field effect scanning electron microscopic (FESEM) investigation showed that the average diameter of ZnO NWs was about 70 nm and the typical lengths varied from $3{\sim}4{\mu}m$.

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A Study on Structural and Dielectric Properties of the (Ba,Sr)TiO$_3$ Thin Films Prepared by Laser Ablation (레이저 어블레이션법으로 제작될 (Ba, Sr)TiO$_3$ 박막의 구조 및 유전특성에 관한 연구)

  • 주학림;김성구;장낙원;마석범;백동수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.122-125
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    • 1999
  • (Ba$_{0.6}$Sr$_{0.4}$)TiO$_3$(BST) thin films were fabricated with different deposition temperature and oxygen pressure by Pulsed Laser Deposition(PLD). Energy Dispersive Spectroscopy(EDS) proved that BST thin films prepared by PLD have almost the same stoichiometric composition as the BST target materials. This BST thin films were fully crystallized at $650^{\circ}C$, 300mTorr oxygen pressure and showed a maximum dielectric constant value of $\varepsilon$$_{t}$=684 and dielectric loss was 0.01 at 75$0^{\circ}C$, 300mTorr oxygen pressure.ssure.

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A Study on Electrical Characteristics of the PLZT Thin Film Acorrding to Thickness for DRAM Capacitor (DRAM소자용 PLZT 박막의 두께에 따른 전기적 특성에 관한 연구)

  • 박용범;장낙원;마석범;김성구;최형욱
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.278-281
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    • 1999
  • PLZT thin films on Pt/Ti/SiO$_2$/Si substrate were fabricated with different Thickness by pulsed laser deposition. 14/50/50 PLZT thin film showed a maximum dielectric constant value of $\varepsilon$$_{t}$=985 at 5000$\AA$, and $\varepsilon$$_{t}$=668 at 2000A. P-EI hysteresis loop of 14/50/50 PLZT thin film was slim ferroelectric. Leakage current density of 14/50/70 PLZT thin film was 10$^{-8}$ A/$\textrm{cm}^2$ at 2000$\AA$.EX>.

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Preparation of LaGaO3 Based Oxide Thin Film on Porous Ni-Fe Metal Substrate and its SOFC Application

  • Ju, Young-Wan;Matsumoto, Hiroshige;Ishihara, Tatsumi;Inagaki, Toru;Eto, Hiroyuki
    • Journal of the Korean Ceramic Society
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    • v.45 no.12
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    • pp.796-801
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    • 2008
  • $LaGaO_3$ thin film was prepared on Ni-Fe metal porous substrate by Pulsed Laser Deposition method. By the thermal reduction, the dense $NiO-{Fe_3}{O_4}$ substrate is changed to a porous Ni-Fe metal substrate. The volumetric shrinkage and porosity of the substrate are controlled by the reduction temperature. It was found that a thermal expansion property of the Ni-Fe porous metal substrate is almost the same with that of $LaGaO_3$ based oxide. $LaGaO_3$ based electrolyte films are prepared by the pulsed laser deposition (PLD) method. The film composition is sensitively affected by the deposition temperature. The obtained film is amorphous state after deposition. After post annealing at 1073K in air, the single phase of $LaGaO_3$ perovskite was obtained. Since the thermal expansion coefficient of the film is almost the same with that of LSGM film, the obtained metal support LSGM film cell shows the high tolerance against a thermal shock and after 6 min startup from room temperature, the cell shows the almost theoretical open circuit potential.

CHaracteristics of (Pb,La)T$TiO_3$ Thin Film by Deposition Condition of Pulsed Laser Ablation (레이저 어블레이션에 의한 (Pb,La)$TiO_3$박막의 제작조건에 따른 특성)

  • 박정흠;박용욱;마석범
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.12
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    • pp.1001-1007
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    • 2001
  • In this study, high dielectric materials, (Pb,La)Ti $O_3$ thin films were fabricated by PLD (Pulsed Laser Deposition) method and investigated in terms of structural and electrical characteristics in order to develope the dielectric materials for the use of new capacitor layers of Giga bit-level DRAM. The deposition conditions were examined in order to fabricate uniform thin films through systematic changes of oxygen pressures and substrate temperature. The uniform thickness and smooth morphology of (P $b_{0.72}$L $a_{0.28}$)Ti $O_3$ thin films were obtained at the conditions of substrate-target distance 5.5[cm], laser energy density 2.1[J/$\textrm{cm}^2$], oxygen pressure 200[mTorr] and substrate temperature 500[$^{\circ}C$]. After the (P $b_{0.72}$L $a_{0.28}$)Ti $O_3$ thin films were fabricated under the above conditions, they were post-annealed by RTA process in order to increase the dielectric constant. The film thickness of 1200 [$\AA$] had dielectric constant 821. Assuming that operating voltage is 2V, leakage current density of (P $b_{0.72}$L $a_{0.28}$)Ti $O_3$ thin films would result into 10$^{-7}$ [A/$\textrm{cm}^2$] and satisfied the specification of 256M DRAM planar capacitor, 4$\times$10$^{-7}$ [A/$\textrm{cm}^2$]m}^2$]

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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.