A New Thermophoretic Precipitator for Collection of Nanometer-Sized Aerosol Particles (original) (raw)
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2019
The reduction of particles in ultrapure water (UPW) systems is driven primarily by the semiconductor industry. Particles that can produce defects in chip manufacturing and potentially reduce yield, are now identified to be 10 nm and smaller. Isolating and collecting particles in this size range using the classical filtration technique of sieving is limited, time consuming and in many cases, ineffective. Additionally, locating 10 nm particles on a 25 mm filter with a total surface area of more than 500 mm (500,000,000 nm) is highly labor intensive. Focused Aerosol Deposition (FAD) is a technique that combines extraction of nanoparticles from UPW via aerosolization with focused droplet deposition on an SEMready stub. This provides an extremely localized collection of particles as small as 5 nm. Improvements in aerosol focusing, evaporation management and direct deposition on scanning electron microscope ready media has resulted in a focal point as small as 0.04 mm with repeatable posi...
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