• 제목/요약/키워드: Pulse laser deposition

검색결과 61건 처리시간 0.023초

펄스 레이저 증착법에 의해 제작된 Laser pulse repetition rate의 변화에 따른 $Pb(Zr_{0.48}Ti_{0.52})O_3$ (PZT) 박막의 전기적 특성 (Effect of Laser Pulse Repetition Rate on the Electrical Properties of $Pb(Zr_{0.48}Ti_{0.52})O_3$ (PZT) Thin Films grown by Pulsed Laser Deposition)

  • 이동화;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.11-12
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    • 2005
  • [ $Pb(Zr_{0.48}Ti_{0.52})O_3$ ] (PZT) thin films were deposited on Pt(111)/Ti/$SiO_2$/Si substrates by pulsed laser deposition. In order to study the effect of different laser pulse repetition rate on the dielectric and ferroelectric properties of PZT thin films,2 Hz and 5 Hz of laser pulse repetition rate were selected. We compared the results of XRD pattern, dielectric constant and hysteresis characteristics. From the experimental data, we found that the electrical properties of PZT thin films which grown ar 2 Hz of laser pulse repetition rate were better than those which grown at 5 Hz of laser pulse repetition rate.

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In-Situ Pulse Laser Annealing 증착에 의한 광학박막의 표면 개선 효과 (Effect of Surface Improvement on Thin Film by In-Situ Laser Annealing Deposition)

  • 이세호;유연석
    • 한국광학회지
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    • 제20권1호
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    • pp.34-40
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    • 2009
  • $MgF_2$, $SiO_2$ 및 ZnS 박막을 물리 증기 증착하는 동안 펄스 레이저(Nd-YAG, 제2고조파 532 nm)로 Annealing 하여 표면 거칠기 특성을 개선하였다. 펄스 반복율이 10 Hz, 펄스폭 5 ns, 파장 532 nm인 펄스레이저로 Annealing한 유리 기판에 증착된 $MgF_2$$SiO_2$ 시료들은 레이저 에너지가 $140\;mJ/cm^2$ 경우에 산란 총량 값이 최소가 되었지만, ZnS 박막의 경우에는 Annealing 레이저광 에너지가 $62\;mJ/cm^2$일 때 산란 총량이 최소값을 나타냈다. AFM을 사용하여 박막시료의 표면 거칠기에 대한 펄스 레이저 Annealing 효과를 측정 하였다. 그 결과는 TIS 측정치와 유사 하여 표면 거칠기는 Annealing 하기위해 조사된 레이저 에너지에 의존 하여 감소하였다.

Laser와 PZT - Target간의 반응과 그에 따른 Plume 형성 및 입자 방출에 관한 연구 (Interaction of Laser Beam with PZT - Target and Observation of Laser - Induced Plume and Particle Ejection)

  • 이병우
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권5호
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    • pp.93-102
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    • 1996
  • Laser-induced plume and laser-target interaction during pulsed laser deposition are demonstrated for a lead zirconate titanate (PZT). A KrF excimer laser (wavelength 248nm) was used and the laser was pulsed at 20Hz, with nominal pulse width of 20ns. The laser fluence was~$16J/cm^2,$ with 100mJ per pulse. The laser-induced plasma plume for nanosecond laser irradiation on PZT target has been investigated by optical emission spectra using an optical multichannel analyzer(OMA) and by direct observation of the plume using an ICCD high speed photography. OMA analysis showed two distinct ionic species with different expansion velocities of fast or slow according to their ionization states. The ion velocity of the front surface of the developing plume was about $10^7$cm/sec and corresponding kinetic energy was about 100eV. ICCD photograph showed another kind of even slower moving particles ejected from the target. These particles considered expelled molten parts of the target. SEM morphologies of the laser irradiated targets showed drastic melting and material removal by the laser pulse, and also showed the evidence of the molten particle ejection. The physics of the plasma(plume) formation and particle ejection has been discussed.

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The PL Characteristics of ZnO Thin Film on Flexible Polymer by Pulse Laser Deposition

  • Choi, Young-Jin;Lee, Cheon
    • Transactions on Electrical and Electronic Materials
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    • 제13권5호
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    • pp.245-247
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    • 2012
  • In this study, ZnO films have been grown on PES (polyethersulfone) of flexible polymer substrate by PLD (pulsed laser deposition) and characterized for crystalline and optical properties. Growing conditions were changed with substrate temperatures ranging from 50 to $200^{\circ}C$ and laser power density ranging from 0.2 to $0.4J/cm^2$. When ZnO thin films are deposited at low temperature with a small laser power density, the (002) peaks of XRD to signify the crystal quality of ZnO thin films appear to be very weak and the (101) peaks to signify the chemical composition of oxygen and zinc are strong. The (002) peaks increase with the substrate temperature and laser power density because the energy needed for the supply of the combination regarding zinc and oxygen has increased. In this study, the best condition for growing ZnO thin film on PES is at a substrate temperature of $200^{\circ}C$ and with a laser density of $0.3J/cm^2$. The characteristics of PL were measured by UV and green luminescence.

레이저 층착법에 의해 형성된 $Gd_{2}O_{3}$박막의 구조와 광학적 특성 (Structure and optical Properties of $Gd_{2}O_{3}$ thin films on glass Prepared by Pulsed Laser Deposition)

  • 이경철;이천;조신호;박중철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.362-364
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    • 2001
  • The pulsed laser deposition(PLD) technology was used for the deposition of phosphor substance, Gd$_2$O$_3$on commercial glass. An Nd:YAG laser was employed for the deposition (wavelength 266nm, energy up to 100mJ/pu1se, pulse duration is 5ns and repetition rate 10 Hz). With respect to films grown by conventional PLD, this study exhibited the condition at normal temperature. Experiments were done without any reactive gas at a pressure of 10$^{-5}$ ~10$^{-6}$ Torr using second harmonic(λ=532 nm) and fourth harmonic(λ=266 nm) Nd:YAG laser. Analyses of the deposited material grown are performed by EDX, AFM, SEM, PL meseurements.

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Laser Ablated Carbon Thin Film from Carbon Nanotubes and Their Property Studies

  • Sharon, Maheshwar;Rusop, M.;Soga, T.;Afre, Rakesh A.
    • Carbon letters
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    • 제9권1호
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    • pp.17-22
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    • 2008
  • A carbon nanotube (CNT) of diameter ~20 nm has been synthesized by spray pyrolysis of turpentine oil using Ni/Fe catalyst. Pellet of CNTs has been used as a target to produce semiconducting carbon thin film of band gap 1.4 eV. Presence of oxygen pressure in the pulse laser deposition (PLD) chamber helped to control the $sp^3/sp^2$ ratio to achieve the desired band gap. Results are discussed with the help of Raman spectra, SEM TEM micrographs and optical measurements suggest that semiconducting carbon thin film deposited by PLD technique has retained its nanotubes structure except that its diameter has increased from 20 nm to 150 nm.

Indium Tin Oxide Thin Films Grown on Polyethersulphone (PES) Substrates by Pulsed-Laser Deposition for Use in Organic Light-Emitting Diodes

  • Kim, Kyung-Hyun;Park, Nae-Man;Kim, Tae-Youb;Cho, Kwan-Sik;Sung, Gun-Yong;Lee, Jeong-Ik;Chu, Hye-Yong
    • ETRI Journal
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    • 제27권4호
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    • pp.405-410
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    • 2005
  • High quality indium tin oxide (ITO) thin films were grown by pulse laser deposition (PLD) on flexible polyethersulphone (PES) substrates. The electrical, optical, and surface morphological properties of these films were examined as a function of substrate temperature and oxygen pressure. ITO thin films, deposited by PLD on a PES substrate at room temperature and an oxygen pressure of 15 mTorr, have a low electrical resistivity of $2.9{\times}10^{-4}{\Omega}cm$ and a high optical transmittance of 84 % in the visible range. They were used as the anode in organic light-emitting diodes (OLEDs). The maximum electro luminescence (EL) and current density at 100 $cd/m^2$ were 2500 $cd/m^{2}$ and 2 $mA/m^{2}$, respectively, and the external quantum efficiency of the OLEDs was found to be 2.0 %.

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레이저 마스킹과 직류전원을 이용한 선택적 전해도금 (Selective Electrodeposition Using Laser Masking and DC Voltage)

  • 신홍식;김성룡
    • 한국생산제조학회지
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    • 제24권1호
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    • pp.75-80
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    • 2015
  • This paper proposes a selective electrodeposition process that uses laser masking and a DC voltage. Selective electrodeposition using laser masking and a DC voltage is more efficient than that using laser masking and a pulse voltage. In other words, electrodeposition with a DC voltage allows for precise selective deposition without the limitation of the deposition region. Also, a selective electrodeposition method that uses laser masking and DC voltage can reduce the electrodeposition time. The characteristics of a copper layer deposited by laser masking and DC voltage were examined under various conditions. A selective copper layer with various micro patterns of $2{\mu}m$ thickness was successfully fabricated.

펄스레이저 증착법에 의해 성장된 ZnO 박막의 특성 관찰 (Investigating of the Properties of ZnO Film Synthesized by Pulsed Laser Deposition)

  • 최재완;지현진;정창욱;이보화;김규태
    • 한국전기전자재료학회논문지
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    • 제24권2호
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    • pp.108-111
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    • 2011
  • The semiconducting material of ZnO in II-VI group was well known as its good application for photo electronics, chemical sensors and field effect transistors due to the remarkable optical properties with wide energy band gap and great ionic reactivities. Up to now the growth of a good quality of ZnO film has been issued for better performances. Even though there were many deposition methods for making ZnO films, pulse laser deposition methods have been preferred for high crystalline films. In this report, the ZnO film was also created by pulsed laser deposition technique which also showed high crystalinity. By controlling several factors when deposited, it was investigated that the optimal condition for ZnO film formation. Mainly, oxygen partial pressures and growth temperatures were changed when ZnO films were synthesized and followed the characterization by HRXRD and AFM.

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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    • 제6권3호
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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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