Protocol for Measuring Destruction or Removal Efficiency (DRE) of Fluorinated Greenhouse Gas Abatement Equipment in Electronics Manufacturing

PREFACE The U. S. Environmental Protection Agency (EPA) initiated preparation of this Protocol as part of its commitment to assist the PFC Emissions Reduction/Climate Partnership for the Semiconductor Industry (the Partnership) to achieve its voluntary fluorinated greenhouse gas (F-GHG) emission reduction and reporting goals. F-GHGs include the most powerful and often persistent greenhouse gases such as perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), sulfur hexafluoride (SF 6), and nitrogen trifluoride (NF 3). The Partnership's reduction goal is to decrease F-GHG emissions to 10 percent below the 1995 base-year amounts by 2010. Several F-GHG-reducing options are available, with reduction-efficiencies ranging from 10 to 99 percent or higher. Practical reduction strategies comprise modifying manufacturing processes— optimizing processes and switching to alternative gases with lower emissions potential—as well as installing point-of-use (POU) F-GHG abatement systems. Detailed methods for measuring F-GHG emissions from manufacturing processes were standardized in 1999 and are documented and continually updated in the industry's International Semiconductor Manufacturing Initiative (ISMI) Guidelines. Standard methods for measuring and documenting the destruction or removal efficiencies (DREs) from POU abatement systems have lagged those for measuring process emissions. One objective of this document (the Protocol) is to align measurement of emissions from manufacturing processes with those from abatement systems. The Protocol builds on three DRE measurement studies of POU F-GHG thermal abatement systems conducted onsite at three U. S. semiconductor manufacturing facilities, each a member of the Partnership. Air Products performed and documented the measurements under subcontract to ICF International, who was contracted by EPA to support development of the Protocol. In total, four abatement systems were tested and all were connected to plasma-enhanced chemical vapor deposition (PECVD) or etch process equipment. During the studies, DRE measurements were made with the plasma on (during wafer processing) and with the plasma off. A key feature of these measurement studies was development and testing of a reliable method for measuring the dilution of F-GHGs during abatement. This is the third version of the Protocol. It reflects two rounds of external reviews, one each for the first and second version. The first version, prepared after measurements were made at two facilities, was circulated to Semiconductor Industry Association (SIA), Japan Electronics and Information Technology Industries Association (JEITA), and Taiwan's Industrial Technology Research Institute (ITRI) as well as to abatement manufacturers and industry consultants experienced in measuring the DRE of F-GHG abatement systems. The comments and responses to those comments were documented and …