Thermophoretic effect of particle deposition on a free standing semiconductor wafer in a clean room

Ye, Yan; Pui, David Y.H.; Liu, B. Y H; Opiolka, S.; Blumhorst, S.; Fißan, H.

doi:10.1016/0021-8502(91)90093-w

Cited by 120 publications

(68 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally, Gr/Rc2 > 10 is used as a criterion to determine the importance of buoyancy (Ye et al 1991). In this work, G r /~e~ is smaller than 0.03 for the temperature difference of 0°C to 4°C.…”

Section: Introductionmentioning

confidence: 93%

“…Ye et al (1991) measurcd average deposition velocity of PSL spheres ranging from 1 to 5 p m in diameter for AT, in the range of 10"-40°C. The experimental results of Ye et al indicated that AT, should be kept smaller than 10°C to make it possible to mcasure the deposition velocity for particles of diameter smaller than 1 pm.…”

Section: Thermophoretic Effect On the Average Deposition Velocitymentioning

confidence: 99%

“…The negative thermophoretic effect refers to the situation where the deposition of particles increases when the temperature of the wafer surface decreases below that of the surrounding air. Ye et al (1991) studied both experimentally and numerically the positive thermophoretic effect on particle deposition. They measured average deposition velocity of PSL spheres ranging from 1 to 5 p m in diameter with thermophoretic cffect for a temperature difference between the wafer surface and the surrounding air of 10°C to 40°C.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Measurements and Control of Particle Deposition Velocity on a Horizontal Wafer with Thermophoretic Effect

Lee

Park

1995

Aerosol Science and Technology

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 93%

Section: Thermophoretic Effect On the Average Deposition Velocitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Measurements and Control of Particle Deposition Velocity on a Horizontal Wafer with Thermophoretic Effect

Lee

Park

1995

Aerosol Science and Technology

View full text Add to dashboard Cite

“…Deposition velocity, defined as the ratio of particle flux toward a surface to aerosol concentration above that surface, is accepted as the criterion to assess the level of particulate contamination. Previous researches of deposition velocity have focused on the horizontal free-standing wafer to which air flow is perpendicular (Liu and Ahn 1987;Opiolka et al 1994;Otani et al 1989;Pui et al 1990;Ye et al 1991;Yook et al 2007b). Since horizontal wafers or photomasks are transported horizontally by robots in the cleanroom, aerosol particles may approach and contaminate the wafers or photomasks by the air flow parallel to the surfaces.…”

Section: Introductionmentioning

confidence: 99%

Deposition Velocity onto an Inverted Flat Surface in a Laminar Parallel Flow

Choi

Yook

2010

Aerosol Science and Technology

View full text Add to dashboard Cite

Wafers and photomasks in the cleanroom are exposed to airflows not only vertical but also parallel to the surfaces. In this study, Gaussian Diffusion Sphere Model (GDSM) was adjusted to predict deposition velocity onto an inverted flat surface in a laminar parallel flow by considering Brownian diffusion and gravitational settling of aerosol particles. The GDSM was validated by comparing with the simulation of solving flow and aerosol-concentration fields for an inverted flat surface and also with the mass transfer correlation for a finite flat surface of circular or rectangular areal shape. The GDSM was proven to correctly predict the deposition velocities onto the inverted flat surfaces, by taking one hour with a 2.66-GHz-CPU personal computer to obtain deposition velocities for 20 particle sizes, which is a very much shorter time compared with the time for simulating the flow and aerosolconcentration fields. Deposition velocities onto the inverted 45-cmwafer and 15.2-cm-photomask in parallel airflows were predicted using the GDSM, for the particle size ranging from 0.003 to 1.5 µm and the airflow velocity varying from 5 to 500 cm/s. The deposition velocity decreased with increasing particle size, with a steep declination especially for particles larger than approximately 0.1 µm. From the qualitative comparison of the deposition velocities onto the inverted square flat surfaces, representing the photomasks with different orientations in the parallel flow, it was suggested to transport the EUVL photomask with its side facing the airflow rather than with its corner confronting the airflow, in order to minimize particulate contamination.

show abstract

“…For example, Chang et al (1999) have carried out numerical calculations to show that the rates of deposition of submicron particles on vertical cooled plates in natural-convection environments are influenced strongly by both thermophoresis and buoyancy. Ye et al (1991) have studied numerically and experimentally the deposition of monodisperse aerosol particles on a heated vertical wafer surface and found good agreement between measured and computed particle deposition velocities. Sasse et al (1994) have analyzed particle migration under thermophoretic and buoyant forces to provide guidelines for the design of filters and to predict their efficiency of particle removal.…”

Section: Introductionmentioning

confidence: 80%

A Thermophoretic Sherwood Number for Characterizing Submicron-Particle Mass Transfer in Laminar Wall-Bounded Flows

Brereton

Mehravaran

2013

Aerosol Science and Technology

View full text Add to dashboard Cite

New solutions to the Eulerian particle-transport equations are presented which describe concentration profiles in wall-bounded, submicron-particle-laden, one-way coupled flows of gases undergoing advective transport and thermophoresis. These solutions have been deduced for the cases of steady, fully developed, laminar flow of hot gas within pipes and channels with a cold surface at a uniform temperature, when the velocity field and the temperature and particle concentration profiles can be described by their constantproperty forms. They are used to show how the effectiveness with which temperature difference drives particulate mass transport can be characterized by a dimensionless mass-transport coefficient or thermophoretic Sherwood number-the product of a particleconcentration ratio and the heat-transfer Nusselt number-that is useful in making engineering predictions of and comparisons between particulate mass transfer rates in different flows. The solutions also reveal how the concentration profiles in pipe and channel flows undergo inversion during development, changing from low concentrations near the cold surface and high concentration in the bulk flow near the entrance, to low concentrations in the bulk and high ones near the cold surface when the concentration field has developed fully.

show abstract

Thermophoretic effect of particle deposition on a free standing semiconductor wafer in a clean room

Cited by 120 publications

References 11 publications

Measurements and Control of Particle Deposition Velocity on a Horizontal Wafer with Thermophoretic Effect

Measurements and Control of Particle Deposition Velocity on a Horizontal Wafer with Thermophoretic Effect

Deposition Velocity onto an Inverted Flat Surface in a Laminar Parallel Flow

A Thermophoretic Sherwood Number for Characterizing Submicron-Particle Mass Transfer in Laminar Wall-Bounded Flows

Contact Info

Product

Resources

About