Particle Dynamics in a Front-Opening Unified Pod/Load Port Unit Minienvironment in the Presence of a 300 mm Wafer in Various Positions

Hu, Shih−Cheng; Hsiao, Tong Rong

doi:10.1080/027868290920115

Cited by 10 publications

(7 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although infectious pathogens do not enter human bodies by the airborne route in the physical contact transmission mode, the air transport characteristics of expiratory droplets affect their surface deposition characteristics. Many studies have shown that ventilation airflow has significant impact on the deposition of aerosols in indoor environments (e.g., Chang et al 2006;Bouilly et al 2005;Hu and Hsiao (2005); etc.). One problem with the studies by Chao and Wan (2006) and is the use of an empty room in order to focus on the effect of airflows generated by mechanical ventilation systems.…”

Section: Introductionmentioning

confidence: 99%

Transport and Removal of Expiratory Droplets in Hospital Ward Environment

Chao

Wan

2008

Aerosol Science and Technology

View full text Add to dashboard Cite

The transport and removal characteristics of expiratory droplets at different supply airflow rates and "coughing" orientations were investigated both numerically and experimentally in a three-bed hospital ward setting. A Lagrangian-based particletracking model with near-wall correction functions for turbulence was employed to simulate the fate of the expiratory droplets. The model was tested against experimental droplet dispersion data obtained in an experimental hospital ward using Interferometric Mie Imaging and a light-scattering aerosol spectrometer. The change in airflow supply rate had insignificant effect on the transport and deposition of very large droplets (initial sizes ≥ 87.5 µm) due to the dominance of gravitational settling on these behaviors. Smaller droplets (initial sizes ≤ 45 µm) exhibited certain airborne behaviors. The effect of thermal plumes from heat sources was observed only when the supply airflow was low and when the droplet size was small, as observed in the vertical mixing patterns of the droplets of various sizes. Larger droplets tended to settle lower and lateral dispersion of the droplets became weak at the low supply airflow rate. The deposition characteristics for different surfaces in the room are described. The heat plumes seemed to obstruct small droplets from being deposited onto heated surfaces. More deposition was predicted in the lateral injection case compared with the vertical injection case. Adopting near-wall correction for turbulence in the model reduced the predicted deposition removal fraction by 25% for 1.5 µm droplets. This reduction became less significant for larger droplets due to the smaller dependence on turbulent diffusion in their deposition. NOMENCLATURECunningham correction factor

show abstract

Section: Introductionmentioning

confidence: 99%

Transport and Removal of Expiratory Droplets in Hospital Ward Environment

Chao

Wan

2008

Aerosol Science and Technology

View full text Add to dashboard Cite

show abstract

“…Particles with moisture in the air not only contaminate wafer itself but also have effect on wire bonding which can generate product defects (Kikyuama et al, 1991;Den et al, 2006;Lin et al, 2010;Lee et al, 2015). To prevent this kind of contamination by exposure to the air, wafers on which chip is formed are stored or moved in the enclosed carrier called front opening unified pod (FOUP) and particles or AMCs remaining on wafers may diffuse into FOUP and contaminate it (Frickinger et al, 2000;Hu et al, 2005;Hu et al, 2009). Particles or AMCs adsorb onto inside of FOUP which can contaminate other wafers and FOUPs like a "contagious disease" and therefore various researches on FOUP cleaning and purge are in progress (Hu and Tsao, 2006;Hu et al, 2007;Yoo et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Influence of Fluoride Ions Contamination in Front Opening Unified Pod (FOUP) Generating Defective Bonding Pad

Kwon

Hwang

Kim

et al. 2017

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

We analyzed defective bonding pad in various ways and determined the causes of defects that boosts oxidation of aluminium by fluoride residue on surface of pad with moisture. Additionally, we compared and evaluated methods to minimize pad defects in aspects such as etching and wafer storage environment. In case of wafers after pad open etching process using common CF 4 stored in FOUP, the concentration of fluoride ions in FOUP was 230 ng L -1 and it decreased down to 170 ng L -1 when Ar sputtering step was added after using CF 4 . Also under the same condition, fluoride ion concentration in FOUP decreased down to 20 ng L -1 when nitrogen purge was introduced for 10 minutes to the FOUP where wafers were stored and the moisture also decreased from 40% before purge to 10% after purge. As a result of observation on pad surface after storing wafers in FOUP for 120 hours under each condition, negligible amount of defects were found when nitrogen was purged. Therefore, we conclude that defects on pad were generated by existing fluoride ions after etching process and moisture in the air.

show abstract

“…An air recirculation system of a raised-floor return ventilation arrangement has been employed to industrial cleanrooms and received increased attention (Hu et al, 1996;Fu et al, 2001;Hu et al, 2002aHu et al, , 2002bHu and Chuah, 2003;Hu and Wu, 2003;Hu and Hsiao, 2005;Hu and Chen, 2007;Hu et al, 2009). In such raised-floor return air system, the clean air is introduced from ceiling grilles and then extracted from the raised perforated floor.…”

Section: Introductionmentioning

confidence: 99%

Effects of the Removal of 0.1 µm Particles in Industrial Cleanrooms with a Fan Dry Coil Unit (FDCU) Return System

Lin

Tung

et al. 2010

Aerosol Air Qual. Res.

Self Cite

View full text Add to dashboard Cite

A wall-return ventilation system, containing ceiling-supply and wall-return air grilles, is traditionally used in nonunidirectional airflow cleanrooms. In such a wall-return cleanroom, the pathways of return airflow towards the wall-return grilles may be affected by locations and layouts of the production lines and tool equipment; moreover, especially considering the needs for relocation of production lines and rearrangement of tool equipment in the industrial cleanrooms, this study proposed a fan dry coil unit (FDCU) return system, containing ceiling-supply and ceiling-return air grilles, and conducted experimental works in a full-scale cleanroom to investigate the performance of the innovative and traditional ventilation systems. The influences of air change rates and supply air plenum pressures on the removal of 0.1 μm particles were examined in the experiment. Results presented in this paper were subject to the particle size of 0.1 μm. The FDCUreturn ventilation arrangement may provide viable solutions to effective contamination control. The results showed that the innovative FDCU-return system can effectively eliminate about 50% of 0.1 μm particles from the cleanrooms more than the conventional wall-return system. Moreover, the outcomes from this study suggested that particle removal rates for the given cleanrooms were significantly affected by air change rates.

show abstract

Particle Dynamics in a Front-Opening Unified Pod/Load Port Unit Minienvironment in the Presence of a 300 mm Wafer in Various Positions

Cited by 10 publications

References 1 publication

Transport and Removal of Expiratory Droplets in Hospital Ward Environment

Transport and Removal of Expiratory Droplets in Hospital Ward Environment

Influence of Fluoride Ions Contamination in Front Opening Unified Pod (FOUP) Generating Defective Bonding Pad

Effects of the Removal of 0.1 µm Particles in Industrial Cleanrooms with a Fan Dry Coil Unit (FDCU) Return System

Contact Info

Product

Resources

About