• Title/Summary/Keyword: 입자 침착속도

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Measurement of Particle Deposition Velocity Toward a Vertical Wafer Surface (수직 웨이퍼상의 입자 침착속도의 측정)

  • Bae, G.N.;Lee, C.S.;Park, S.O.;Ahn, K.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.3
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    • pp.521-527
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    • 1995
  • The average particle deposition velocity toward a vertical wafer surface in a vertical airflow chamber was measured by a wafer surface scanner(PMS Model SAS-3600). Polystyrene latex(PSL) spheres with diameters between 0.3 and $0.8{\mu}m$ were used. To examine the effect of the airflow velocity on the deposition velocity, experiments were conducted for three vertical airflow velocities ; 20, 30, 50cm/s. Experimental data of particle deposition velocity were compared with those given by prediction model suggested by Liu and Ahn(1987).

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Characteristics of Particle Deposition onto Cleanroom Wall Panel for Varying Particle Charging Rates (입자하전량에 따른 클린룸 수직벽체로의 입자침착 특성)

  • Kim, Jong-Jun;Noh, Kwang-Chul;Sung, Sang-Chul;Baek, Sun-Ho;Oh, Myung-Do
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.725-730
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    • 2008
  • In this study, we found out charged particle's deposition characteristic by experiments of $0.5{\mu}m$, $1.0{\mu}m$, $3.0{\mu}m$ size particle's concentration decay. We carried out the experiments on charged particle deposition onto the vertical cleanroom wall panel and some other fundamental experiments. The particle deposition mechanism is consist of sedimentation, convection, diffusion, thermophoresis, electrostatic and so on. Particle size determines mainly working deposition mechanism. The charged particle is made with corona discharge that are constituted field charging and diffusion charging. In addition, this combinational mechanism is called combined charging. The type of corona discharge determines quantity of particle electrical charge. In conclusion, we assumed that quantity of particle electrical charge accelerations deposition velocity onto the vertical cleanroom wall panel and proved it. And we figured out particle's deposition characteristic through compared between our experiment's results.

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Measurement of Particle Deposition Velocity toward a Horizontal Semiconductor Wafer Using a Wafer Surface Scanner (Wafer Surface Scanner를 이용한 반도체 웨이퍼상의 입자 침착속도의 측정)

  • Bae, G.N.;Park, S.O.;Lee, C.S.;Myong, H.K.;Shin, H.T.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.5 no.2
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    • pp.130-140
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    • 1993
  • Average particle deposition velocity toward a horizontal semiconductor wafer in vertical airflow is measured by a wafer surface scanner(PMS SAS-3600). Use of wafer surface scanner requires very short exposure time normally ranging from 10 to 30 minutes, and hence makes repetition of experiment much easier. Polystyrene latex (PSL) spheres of diameter between 0.2 and $1.0{\mu}m$ are used. The present range of particle sizes is very important in controlling particle deposition on a wafer surface in industrial applications. For the present experiment, convection, diffusion, and sedimentation comprise important agents for deposition mechanisms. To investigate confidence interval of experimental data, mean and standard deviation of average deposition velocities are obtained from more than ten data set for each PSL sphere size. It is found that the distribution of mean of average deposition velocities from the measurement agrees well with the predictions of Liu and Ahn(1987) and Emi et al.(1989).

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Analysis on Particle Deposition onto a Heated Rotating Disk with Electrostatic Effect (정전효과가 있는 가열 회전원판으로의 입자침착 해석)

  • 유경훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.5
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    • pp.424-432
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    • 2002
  • Numerical analysis has been conducted to characterize deposition rates of aerosol particles onto a heated, rotating disk with electrostatic effect under the laminar flow field. The particle transport mechanisms considered were convection, Brownian diffusion, gravitational settling, thermophoresis and electrophoresis. The aerosol particles were assumed to have a Boltzmann charge distribution. The electric potential distribution needed to calculate local electric fields around the disk was calculated from the Laplace equation. The Coulomb, the image, the dielectrophoretic and the dipole-dipole forces acting on a charged particle near the conducting rotating disk were included in the analysis. The averaged particle deposition vetocities and their radial distributions on the upper surface of the disk were calculated from the particle concentration equation in a Eulerian frame of reference, along with a rotation speed of 0∼1,000rpm, a temperature difference of 0∼5K and a charged disk voltage of 0∼1000V.Finally, an approximate deposition velocity model for the rotating disk was suggested. The present numerical results showed relatively good agreement with the results of the present approximate model and the available experimental data.

Analysis on Particle Deposition on a Heated Rotating Disk (가열되는 회전원판으로의 입자 침착 해석)

  • Yu, Gyeong-Hun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.2
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    • pp.245-252
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    • 2002
  • Numerical analysis was conducted to characterize particle deposition on a horizontal rotating disk with thermophorectic effect under laminar flow field. The particle transport mechanisms considered were convection, Brownian diffusion, gravitational settling and thermophoresis. The averaged particle deposition velocities and their radial distributions for the upper surface of the disk were calculated from the particle concentration equation in a Eulerian frame of reference for rotating speeds of 0∼1000rpm and temperature differences of 0∼5K. It was observed from the numerical results that the rotation effect of disk increased the averaged deposition velocities, and enhanced the uniformity of local deposition velocities on the upper surface compared with those of the disk at rest. It was also shown that the heating of the disk with ΔT=5K decreased deposition velocity over a fairly broad range of particle sizes. Finally, an approximate deposition velocity model for the rotating disk was suggested. The comparison of the present numerical results with the results of the approximate model and the available experimental results showed relatively good agreement between them.

Thermophoretic Effect on Particle Deposition Toward a Horizontal Wafer (열영동력이 수평 웨이퍼상의 입자침착에 미치는 영향)

  • 배귀남;박승오;이춘식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.1
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    • pp.175-183
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    • 1994
  • To investigate thermophoretic effect on particle deposition, average deposition velocity toward a horizontal wafer surface in vertical airflow is measured keeping the wafer surface temperature different from the surrounding air temperature. In the present measurement, the temperature difference is maintained in the range from -10 to $4^{\circ}$ C Polystyrene latex (PSL) spheres of diameter between 0.3 and 0.8 .mu.m are used for the experiment. The number of particles deposited on a wafer surface is estimated from the measurements using a wafer surface scanner (PMS SAS-3600). Experimental data are compared with prediction model results.

Particle Deposition Characteristics with Electrostatic Effect on Semiconductor Wafers (정전효과를 고려한 반도체 웨이퍼의 입자침착 특성)

  • Lee, Kun-Hyung;Chae, Seung-Ki;Moon, Young-June
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.779-785
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    • 2006
  • Particle transport and deposition characteristics on semiconductor wafers inside the chamber were experimentally investigated via a particle generation & deposition system and a wafer surface scanner. Especially the relation between particle size($0.083{\sim}0.495{\mu}m$) and particle deposition velocity with ESA(Electrostatic Attraction) effect was studied. Spot deposition technique with the deposition system using nozzle type outlets of the chamber was newly conducted to derive particle deposition velocity and all experiment results were compared with the previous study and were in a good agreement as well.

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Analysis on Particle Deposition onto a Horizontal Semiconductor Wafer at Vacuum Environment (진공환경에서 수평 웨이퍼 표면으로의 입자침착 해석)

  • Yoo, Kyung-Hoon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.12
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    • pp.1715-1721
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    • 2002
  • Numerical analysis was conducted to characterize the gas flow field and particle deposition on a horizontal freestanding semiconductor wafer under the laminar flow field at vacuum environment. In order to calculate the properties of gas, the gas was assumed to obey the ideal gas law. The particle transport mechanisms considered were convection, Brownian diffusion and gravitational settling. The averaged particle deposition velocities and their radial distributions fnr the upper surface of the wafer were calculated from the particle concentration equation in an Eulerian frame of reference for system pressures of 1 mbar~1 atm and particle sizes of 2nm~10$^4$ nm(10 ${\mu}{\textrm}{m}$). It was observed that as the system pressure decreases, the boundary layer of gas flow becomes thicker and the deposition velocities are increased over the whole range of particle size. One thing to be noted here is that the deposition velocities are increased in the diffusion dominant particle size range with decreasing system pressure, whereas the thickness of the boundary layer is larger. This contradiction is attributed to the increase of particle mechanical mobility and the consequent increase of Brownian diffusion with decreasing the system pressure. The present numerical results showed good agreement with the results of the approximate model and the available experimental data.

Numerical Simulation of Particle Deposition on a Wafer Surface (웨이퍼 표면상의 입자침착에 관한 수치 시뮬레이션)

  • 명현국;박은성
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.9
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    • pp.2315-2328
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    • 1993
  • The turbulence effect of particle deposition on a horizontal free-standing wafer in a vertical flow has been studied numerically by using the low-Reynolds-number k-.epsilon. turbulence model. For both the upper and lower surfaces of the wafer, predictions are made of the averaged particle deposition velocity and its radial distribution. Thus, it is now possible to obtain local information about the particle deposition on a free-standing wafer. The present result indicates that the particle deposition velocity on the lower surface of wafer is comparable to that on the upper one in the diffusion controlled deposition region in which the particle sizes are smaller than $0.1{\mu}m$. And it is found in this region that, compared to the laminar flow case, the averaged deposition velocity under the turbulent flow is about two times higher, and also that the local deposition velocity at the center of wafer is high equivalent to that the wafer edge.

Analysis on particle deposition onto a heated, horizontal free-standing wafer with electrostatic effect (정전효과가 있는 가열 수평웨이퍼로의 입자침착에 관한 해석)

  • Yoo, Kyung-Hoon;Oh, Myung-Do;Myong, Hyon-Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.10
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    • pp.1284-1293
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    • 1997
  • The electrostatic effect on particle deposition onto a heated, Horizontal free-standing wafer surface was investigated numerically. The deposition mechanisms considered were convection, Brownian and turbulent diffusion, sedimentation, thermophoresis and electrostatic force. The electric charge on particle needed to calculate the electrostatic migration velocity induced by the local electric field was assumed to be the Boltzmann equilibrium charge. The electrostatic forces acted upon the particle included the Coulombic, image, dielectrophoretic and dipole-dipole forces based on the assumption that the particle and wafer surface are conducting. The electric potential distribution needed to calculate the local electric field around the wafer was calculated from the Laplace equation. The averaged and local deposition velocities were obtained for a temperature difference of 0-10 K and an applied voltage of 0-1000 v.The numerical results were then compared with those of the present suggested approximate model and the available experimental data. The comparison showed relatively good agreement between them.