• Title/Summary/Keyword: Ion sputtering

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Sputtering of Fe(100) Substrate Due to Energetic Ion Bombardments: Investigation with Molecular Dynamics Simulations (분자 동역학 모사를 이용한 Fe(100) 표면의 스퍼터링 해석)

  • Kim Dong-Ho
    • Journal of the Korean institute of surface engineering
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    • v.39 no.2
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    • pp.76-81
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    • 2006
  • Molecular dynamics simulations were carried out to investigate physical sputtering of Fe(100) substrate due to energetic ion bombardments. Repulsive interatomic potentials at short internuclear distances were determined with ab initio calculations using the density functional theory. Bohr potentials were fitted to the ab initio results on diatomic pairs (Ar-Fe, Fe-Fe) and used as repulsive screened Coulombic potentials in sputtering simulations. The fitted-Bohr potentials improve the accuracy of the sputtering yields predicted by molecular dynamics for sputtering of Fe(100), whereas Moliere and ZBL potentials were found to be too repulsive and gave relatively high sputtering yields. In spite of assumptions and limitations in this simulation work, the sputtering yields predicted by the molecular dynamics method were in fairly good accordance with the obtainable experimental data in absolute values as well as in manner of the variation according to the Incident energy. Threshold energy for sputtering of Fe(100) substrate was found to be about 40 eV. Additionally, distributions of kinetic energies of sputtered atoms and their original depths could be obtained.

Sputtering yield and secondary electron emission coefficient ($\gamma$) of the MgO, $MgAl_2O_4$ and $MgAl_2O_4/MgO$ thin film grown on the Cu substrate by using the Focused Ion Beam

  • Jung, Kang-Won;Lee, H.J.;Jeong, W.H.;Oh, H.J.;Choi, E.H.;Seo, Y.H.;Kang, S.O.;Park, C.W.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.877-881
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    • 2006
  • We obtained sputtering yields for the MgO, $MgAl_2O_4$ and $MgAl_2O_4/MgO$ films using the FIB system. $MgAl_2O_4/MgO$ protective layers have been found to have less $24^{\sim}^30%$ sputtering yield values from 0.24 atoms/ion up to 0.36 atoms/ion than MgO layers with the values from 0.36 atoms/ion up to 0.45 atoms/ion for irradiated $Ga^+$ ion beam whose energies ranged from 10 keV to 14 keV. And $MgAl_2O_4$ layers have been found to have lowest sputtering yield values from 0.88 up to 0.11. It is also found that $MgAl_2O_4/MgO$ and MgO have secondary electron emission $coefficient({\gamma})$ values from 0.09 up to 0.12 for $Ne^+$ ion whose energies ranged from 50 eV to 200 eV.

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Some Peculiarities of Photo-structural Transformations in Amorphous Chalcogenide Glassy Semiconductor Films

  • Prikhodko, O.;Almasov, N.;Korobova, Natalya
    • Journal of information and communication convergence engineering
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    • v.9 no.5
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    • pp.587-590
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    • 2011
  • The absence of deep traps for electrons in the spectrum of $As_{40}Se_{30}S_30$ localized states films obtained by ion sputtering was determined. Bipolar drift of charge carriers was found in amorphous $As_{40}Se_{30}S_30$ films of chalcogenide glassy semiconductors, obtained by ion-plasma sputtering of high-frequency, unlike the films of these materials obtained by thermal evaporation.

XRD Patterns and Bismuth Sticking Coefficient in $Bi_2Sr_2Ca_nCu_{n+1}O_y(n\geq0)$ Thin Films Fabricated by Ion Beam Sputtering Method

  • Yang, Seung-Ho;Park, Yong-Pil
    • Journal of information and communication convergence engineering
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    • v.4 no.4
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    • pp.158-161
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    • 2006
  • [ $Bi_2Sr_2Ca_nCu_{n+1}O_y(n{\geq}0)$ ] thin film is fabricatedvia two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.

Numerical Analysis of the Incident ion Energy and Angle Distribution in the DC Magnetron Sputtering for the Variation of Gas Pressure

  • Hur, Min Young;Oh, Sehun;Kim, Ho Jun;Lee, Hae June
    • Applied Science and Convergence Technology
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    • v.27 no.1
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    • pp.19-22
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    • 2018
  • The ion energy and angle distributions (IEADs) in the DC magnetron sputtering systems are investigated for the variation of gas pressure using particle-in-cell simulation. Even for the condition of collisionless ion sheath at low pressure, it is possible to change the IEAD significantly with the change of gas pressure. The bombarding ions to the target with low energy and large incident angle are observed at low pressure when the sheath voltage drop is low. It is because the electron transport is hindered by the magnetic field at low pressure because of few collisions per electron gyromotion while the ions are not magnetized. Therefore, the space charge effect is the most dominant factor for the determination of IEADs in low-pressure magnetron sputtering discharges.

Numerical Analysis of the Incident Ion Energy and Angle Distribution in the DC Magnetron Sputtering for the Variation of Gas Pressure

  • Hur, Min Young;Oh, Sehun;Kim, Ho Jun;Lee, Hae June
    • Applied Science and Convergence Technology
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    • v.27 no.2
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    • pp.26-29
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    • 2018
  • The ion energy and angle distributions (IEADs) in the DC magnetron sputtering systems are investigated for the variation of gas pressure using particle-in-cell simulation. Even for the condition of collisionless ion sheath at low pressure, it is possible to change the IEAD significantly with the change of gas pressure. The bombarding ions to the target with low energy and large incident angle are observed at low pressure when the sheath voltage drop is low. It is because the electron transport is hindered by the magnetic field at low pressure because of few collisions per electron gyromotion while the ions are not magnetized. Therefore, the space charge effect is the most dominant factor for the determination of IEADs in low-pressure magnetron sputtering discharges.

Nano Patterning on Graphite by Ion-Beam Sputtering

  • Yoon, Sun Mi;Kim, J.S.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.214-214
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    • 2013
  • Ion beam sputtering (IBS) by collision of energetic ions at surfaces is one of the representative methods for physical self-assembly. It is in spotlight as an easy tool to make nano structures in various sizes and shapes by controlling physical variablesWe investigate nano patterning on graphite. We found well-ordered nano ripple patterns after sputtering under the oblique angle and mean wavelengths of these ripples could be controlled as ion fluence increases from sub-10 nm to 80 nm. Each nano ripple is terminated by nano buds, which look like a cotton bud. We also examined the formation of various patterns on graphite by sputtering during swinging the sample at a constant angular velocity that have been never reported.

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Sputtering yield of the MgO thin film grown on the Cu substrate by using the focused ion beam (집속이온빔을 이용한 구리 기판위에 성장한 MgO 박막의 스퍼터링 수율)

  • 현정우;오현주;추동철;최은하;김태환;조광섭;강승언
    • Journal of the Korean Vacuum Society
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    • v.10 no.4
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    • pp.396-402
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    • 2001
  • MgO thin films with 1000 $\AA$ thickness were deposited on Cu substrates by using an electron gun evaporator at room temperature. A 1000 $\AA$ thick Al layer was deposited on the MgO for removing the charging effect of the MgO thin film during the measurements of the sputtering yields. A Ga ion liquid metal was used as the focused ion beam(FIB) source. The ion beam was focused by using double einzel lenses, and a deflector was employed to scan the ion beams into the MgO layer. Both currents of the secondary particle and the probe ion beam were measured, and they dramatically changed with varying the applied acceleration voltage of the source. The sputtering yield of the MgO layer was determined using the values of the analyzed probe current, the secondary particle current, and the net current. When the acceleration voltage of the FIB system was 15 kV, the sputtering yield of the MgO thin film was 0.30. The sputtering yield of the MgO thin film linearly increases with the acceleration voltage. These results indicate that the FIB system is promising for the measurements of the sputtering yield of the MgO thin film.

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Change of Refractive Index and Residual Stresses of Ta2O5 Thin Film Prepared by Dual Ion Beam Sputtering Deposition as the Substrate Temperature and Assist ion Beam Energy (이중 이온빔으로 제작한 Ta2O5 박막의 기판 온도 및 보조 이온빔 에너지에 따른 굴절률과 판류응력의 변화)

  • Yeon, Seok-Gyu;Kim, Yong-Tak;Kim, Hwek-Yung;Kim, Myoung-Jin;Lee, Hyung-Man;Yoon, Dae-Ho
    • Journal of the Korean Ceramic Society
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    • v.42 no.1
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    • pp.28-32
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    • 2005
  • The optical properties and intrinsic stress of $Ta_{2}O_{5}$ thin films deposited by Dual ion-Beam Sputtering: (DIBS) and Single ion-Beam Sputtering (SIBS) were studied as a function of the substrate temperature and assist ion beam voltage. The refractive index showed the maximum value (n = 2.144) at $150^{circ}C$ in the SIBS process. When the substrate temperature has above $150^{circ}C$ in the SIBS process the refractive index decreased. In the DIBS process, the increase of the substrate temperature affected the increase of the refractive index at a maximum value (n = 2.1117, at $200^{circ}C$). The low temperature process $(<100^{circ}C)$ can greatly reduce residual stress with the assist ion gun, but the high temperature process was unaffected. As the assist ion beam voltage increase from 250 to 350 V the refractive index increased to 2.185. However, the refractive index was decreased at the range of 350-650 V, As the assist ion beam voltage increased, the stress of the deposited film decreased to 0.1834 GPa at 650 V.