The Rare Air of the Semiconductor Fab

Microelectronics fabrication plants (fabs) are complex structures that require sophisticated air circulation and control. For management and energy savings, most of the conditioned air inside a fab is recirculated and may carry increasing amounts of contaminants that are produced internally, from humans, materials, chemicals, and equipment. About 5 – 20% of fresh air is provided from outside the fab, which may carry other potential contaminants. Small particles have been a well-controlled concern for decades, but modern microelectronics technology also requires a tight control of gas-phase, airborne molecular contamination (AMC) as it affects product, processes, and equipment. It is no longer possible to manufacture advanced semiconductors without AMC protection.

AMC is typically classified based on SEMI standard F021-00-1016. As technology nodes progress, contaminant sensitivities rise and are a greater influence on wafer yield.

AMC Sources

Internal and external sources of contamination contribute through outgassing of organic species, bases, and acids.