Applying Appropriate Techniques in Environmental Impact Assessment for Air Emissions from Semiconductor Facilities

摘要

Emissions of toxic chemicals from semiconductor facilities into the ambient air must be carefully evaluated to ensure protection of human health and the environment. The emission profile from semiconductor operations is unique in many aspects. Numerous organic and inorganic chemicals with different physical and chemical properties (e.g., toxicity, reactivity, and corrosivity) may be involved in semiconductor processes and emitted into the atmosphere from stack and fugitive sources. Moreover, the type and usage of chemicals may change frequently with the change of processes and products. As such, assessing the environmental impacts (health, safety, and welfare) for air emissions from semiconductor processes requires unique approaches and techniques in order to provide adequate environmental, health, and safety protection while obtaining the flexibility required by the process operations. This paper explores the practical and cost-effective approaches and techniques to address the environmental impact assessment for air emissions based on the typical chemical use and emission characteristics for semiconductor processes. A multi-tiered approach utilizing both screening and refined dispersion modeling techniques will be discussed along with case studies to demonstrate the practices in the United States (U.S.). Special treatment and consideration of emissions, source parameters, and chemical properties (e.g., toxicity) are also studied based on typical air emission characteristics for semiconductor processes. Overall, the approaches and techniques discussed in the paper will demonstrate the best practices in the U.S. to achieve the objective of protecting the human health and welfare in both short-term and long-term periods while obtaining the flexibility in chemical use required by semiconductor processes.