Flammable Exhaust Management - Methods for Analysis and Control
(Micron Technology, Inc., Boise, ID)
Semiconductor processes use many flammable materials. These can be process inputs or generated as byproducts. When used under vacuum conditions the material reaction rate is slowed. However, as the process is exhausted through the vacuum pump and transitions to near atmospheric pressures, the flammability of the waste gas must be evaluated and controlled to prevent fires and explosions which can result in employee injury, equipment damage, and production loss. Best practice for flammable exhaust control is dilution of flammable mixtures yet methods for detailed analysis are not widely published. This presentation will provide flammability calculation methodologies and explore the impact of operational conditions on material flammability. In addition to the technical background for flammability calculations, process examples and engineering controls that can reduce exhaust dilution flows will be presented. Semiconductor manufacturers can use the calculation practices and control options presented to accurately perform process hazard analysis and safely design flammable process exhaust systems.