Frequently Asked Questions
- What are fluorinated GHGs (F-GHGs) and why is EPA concerned?
- How do semiconductor manufacturers use F-GHGs?
- Can F-GHG emissions from semiconductor manufacturing be reduced?
- What was the goal of the PFC Reduction / Climate Partnership for the Semiconductor Industry and was it achieved?
- Will Partners continue to report their GHG emissions data to EPA?
- Will F-GHG emissions from semiconductor manufacturing grow in the future?
1. What are fluorinated GHGs (F-GHGs) and why is EPA concerned?
Fluorinated GHGs used in electronics manufacturing are highly potent greenhouse gases. With global warming potentials (GWPs) in the thousands, F-GHGs absorb infrared radiation (i.e., heat) and trap it in the atmosphere very effectively. Fluorinated GHGs are also generally very stable chemicals and therefore possess atmospheric lifetimes from 264 to 50,000 years. Consequently, these gases will accumulate in the atmosphere and their effect on the climate will be felt by many future generations. Please visit EPA’s Climate Change Web site for more information on the impacts of climate change.
2. How do semiconductor manufacturers use F-GHGs?
Fluorinated GHGs gases are used for both etching intricate circuitry features on silicon wafers and for cleaning chemical vapor deposition (CVD) tool chambers. Fluorinated GHGs are energized and dissociated in plasmas to provide reactive fluorine atoms in the manufacturing tool chambers. In the case of plasma etching, the free fluorine atoms selectively react with and remove insulating and/or conductive materials from the exposed surface of a silicon wafer to create the intricate circuitry patterns found on modern semiconductors. In CVD tool chamber cleaning applications, the fluorine atoms react with and remove excess materials from the surface of the tool chambers themselves. Semiconductor manufacturers also use fluorinated heat transfer fluids and nitrous oxide. Fluorinated heat transfer fluids are used to cool process equipment, control temperature during device testing, clean substrate surfaces and other parts, and for soldering. Nitrous oxide is used for CVD and other manufacturing processes such as chamber cleaning.
3. Can F-GHG emissions from semiconductor manufacturing be reduced?
Yes, F-GHG emissions from semiconductor manufacturing can and are being reduced. Over time, EPA’s Partners have implemented a variety of emission reduction strategies such as optimizing (i.e., fine tuning) their production processes to use and emit less F-GHGs and switching to use alternative input gases, for example NF3, which are utilized more efficiently in the process thereby emitting much less F-GHGs into the exhaust stream. Partners’ individual F-GHG emission reduction strategies vary greatly depending on the companies’ product and equipment mix as well as future business plans.
4. What was the goal of the PFC Reduction / Climate Partnership for the Semiconductor Industry and was it achieved?
The goal of the PFC Reduction/Climate Partnership was to reduce high GWP gases from U.S. and world semiconductor manufacturing by identifying and implementing the most cost-effective strategies and technologies. In April 1999, the U.S. partners and the World Semiconductor Council committed to reduce PFC emissions 10 percent below their 1995 baselines by 2010. Since F-GHG use in Korea and Taiwan was negligible in 1995, their baseline years are 1997 and the average of 1997 and 1999 respectively. The U.S. and international WSC goals were achieved in 2010.
5. Will Partners continue to report their GHG emissions data to EPA?
Yes, under subpart I of EPA’s Greenhouse Gas Reporting Program (40 CFR Part 98), owners or operators of electronics manufacturing facilities that emit equal to or greater than 25,000 metric tons of CO2e per year from F-GHG and N2O emissions from cleaning and etch processes, heat transfer use, and other source categories (e.g., CO2 from stationary combustion facilities) must report GHG emissions from all electronics manufacturing processes and any other source category at the facility for which methods are defined in the rule. Covered facilities were required to begin monitoring GHG emissions on January 1, 2011 in accordance with the methods specified in the rule. The first report was due to EPA by September 28, 2012; subsequent report are due annually thereafter by March 31. Reporters submit their data to EPA electronically through EPA’s Electronic Greenhouse Gas Reporting Tool (e-GGRT). For more information about EPA’s Greenhouse Gas Reporting Program, please see: http://www.epa.gov/ghgreporting/index.html.
6. Will F-GHG emissions from semiconductor manufacturing grow in the future?
Demand for semiconductors and other electronics products manufactured using F-GHGs (e.g., flat panel displays, micro-electro-mechanical systems, and photovoltaic cells) is expected to continue to rise given high demand for high-tech products and renewable energy. Therefore, it is likely that emissions from electronics manufacturing sectors will grow in the future. It will be important to share information with the growing electronics industry to assure they have access to, understand, and implement cost-effective mitigation technologies and strategies to address climate change.