As semiconductor technology advances to the submicro level, Airborne Molecular Contamination (AMC) becomes a major problem that severely affects production processes and yields. The damages caused by AMC during R&D & Manufacturing processes of nanotechnology have been found much worse than the contamination sourced from conventional airborne particulates. To solve AMC problems, an Ultra-Pure Air (UPA) method was explored and experimented. A prototype system with a targeting level at 10 ppt capability has been developed. The system provides an AMC-free environment for nanotechnology R&D & Manufacturing.

The UPA system is composed of three process modules. UV185+254nm are used at first to provide sufficient energy to break the molecular bonds of pollutant. Meanwhile, aerosol droplets are introduced to react with these unstable compounds and form hydrophilic substances. After the previous "immersing photochemical" reaction, the pollutants further go through the compression and condensation processes. During this stage, the nucleation, condensation and growth stages of the aerosols are applied to increase the collision probability between the pollutants and water droplets. Further on, a dehumidifying device removes the water droplets within the air, where the pollutants dissolved in the water are removed together during the dehumidification process. Finally, for the trace amount of pollutants that cannot be treated in the previous two stages, they are then removed by selective molecular sieves and a final filtration device.
This paper will begin with a brief literature review of micro-contamination and clean technology followed by an introduction of UPA system. And then, preliminary results and lessons learned from the exploration and experimental testing will be presented. Finally, conclusion will be made with recommendation for future research.

Key words: airborne molecular contamination, cleanroom, nanotechnology, ultra pure air