In leading edge wafer facilities, particulate filtration and AMC control are not option, but a necessity. Controlling Particulate and Airborne Molecular Contamination (AMC) is a primary concern and requirement for high yield, low reject semiconductor manufacturing. Failure to control particulate and AMC in an electronic cleanroom or facility will also significantly dent a company’s operating profits. The main problems in a cleanroom are contamination of products, tools and processes and odour control.
The MEGAcel line of membrane filters are designed to meet stringnent semicondustor industry cleanroom particulate filtration requirements for fab's, modular, mini and micro-environments. The MegaCel filter is developed to provide extremely high particulate efficiency combined with low pressure drop and negligible off-gassing properties.
The ISO Standard 14644-8 for Cleanrooms and associated Controlled Environments – Part 8 was introduced in 2004 and covers the classification of airborne molecular contamination (AMC) in cleanrooms and associated controlled environments.
To achieve and meet the ISO standard, fab and wafer manufacturers have to pay attention to all areas of their facilities where air is used, handled and required for their processes, including:
- the supply and make up air trajectory
- the recirculated air trajectory (ballroom, mini-environment and enclosed areas as well as fan filter units in localized control areas)
- the exhaust air trajectory
- the mini environment where air purging and air cleanliness is needed
Sources of AMC can be external or internal.
- Internal sources can include offgassing of chemicals used during the manufacturing process and of components and materials or as a result of accidental spills or calamities in the cleanroom itself. Chemical reactions in the minienviroment as a result of short wavelength DUV is also a a source.
- External sources include contaminants brought into the facility via the HVAC make up and supply air system and is influenced by the location and proximity of a facility to exhaust fumes from other industries and processes, vehicle exhaust fumes, the sea, seasonal factors and the wind direction etc.