SF6 usage and emission trends in the TFT-LCD industry

Abstract

Several fluorinated compounds (FCs) used in electronics manufacturing, including SF6, perfluorocarbons (PFCs), and hydrofluorocarbons (HFCs) are extremely potent greenhouse gases. These compounds are classified as global warming pollutants to be controlled by the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol. Thin film transistor liquid crystal display (TFT-LCD) manufacturing is a major source of SF6 emissions, in which these gases are used for equipment cleaning and plasma etching. The respective Environmental Protection Administration of the Republic of China, Taiwan and the Environmental Protection Agency of the United States collaboratively strive in encouraging high technology manufacturers to improve annual reporting of FCs emissions and implement emission reduction practices and technologies.In the TFT-LCD industry, FCs account on average for 30% of total greenhouse gas emissions; 80% of emissions originate from the etching process and 20% from the chemical vapor deposition (CVD) chamber cleaning process, which is in compliance with Taiwan EPA data reports from 2005 to 2010. The leading TFT-LCD manufacturers are Japan, Korea, and Taiwan. The World LCD Industry Cooperation Committee (WLICC) subsequently established an aggressive climate protection action plan in 2001. This study focuses specifically on SF6 usage and emission factors reflecting common TFT-LCD manufacturing practices.