Global Warming Gas Emissions From the Semiconductor Industry

摘要

Recent human activity has increased the concentrations of trace gases in the atmosphere to the point that the combined effect of these gases on global radiative heating could rival that of carbon dioxide. These trace gases include methane, nitrous oxide, chlorofluorocarbons (CFCs), and perfluorocompounds (PFCs). Long atmospheric lifetimes and strong infrared absorption combine to make PFCs potent global warming gases. There are currently no restrictions on the use or availability of PFCs, making it difficult to estimate emissions. The semiconductor industry depends heavily on PFCs for two manufacturing processes: chamber cleanings and film etchings. Alternative chemistries are currently being researched and tested to reduce the use of PFCs in the semiconductor industry. Nitrogen trifluoride (NF_3) shows promise as an alternative to perfluoroethane (C_2F_6) in silicon oxide chamber cleanings because it offers higher utilization rates and decreased gas mass requirements. In addition, NF_3 has a lower global warming potential than C_2F_6, resulting in a substantially lower global warming impact of the process. A case study of a sample manufacturing facility shows that significant reductions in global warming gas emissions can be achieved using alternative chemistries in chamber cleaning processes. Because the equipment and processes used to manufacture semiconductors change rapidly, implementing novel chemistries is a viable strategy in the semiconductor industry.