Environmental health and safety (EHS) investigation of CVD exhaust system: identification and mitigation of potential release of process gases and by-products

摘要

Motorola Semiconductor Products Sector has undergone the initiative to reduce perfluorocompound (PFC) emissions by converting from the standard in-situ cleaning chemistries on chemical vapor deposition (CVD) processes to NF_3-based cleans. As a result, the severity of a post-plasma fluorine release is potentially greater than with the in-situ clean. Motorola conducted a safety evaluation on a typical VCD exhaust system to identify and mitigate the risk of a potential releases. The evaluation utilized a failure modes effects analysis (FMEA) risk assessment to systematically identify the causes that could lead to a potential release of process gases or byproducts. Any release would require an exhaust system failure that results in positive static pressure. Controls to detect a pressure fault and to prevent the release would have to be non-functional The recommendations are divided into three categories. Primary recommendations are essential to risk reduction and release prevention. Secondary recommendations should be considered to further reduce the risk. The tertiary recommendations provide suggestions for future studies.