Various Activities to Reduce Greenhouse Gases including PFCs
Reduction of greenhouse gases including PFCs are also actively pursued
We use perfluorocompounds (PFCs) and other greenhouse gases in the manufacturing process of semiconductors.
The World Semiconductor Committee (WSC), an international semiconductor industry group, selected seven kinds of greenhouse gases (CF4, C2F6, C3F8, C4F8, CHF3, SF6 and NF3) as the subjects for reduction and has a target to reduce total emission of those gases in CY 2010 to 90 % of the amount emitted in CY 1995 (a 10 % reduction).
We introduced six abatement systems with support by the New Energy and Industrial Development Organization (NEDO) in the previous fiscal year and actively promoted the reduction of emissions. The total amount of PFC gas emissions by the Semiconductor & Storage Products Company Group in CY 2010 was equivalent to 400,000 tons of CO2, a reduction of 13 % compared to CY 1995, and we also achieved the WSC target. The fifth plant started operation at Yokkaichi in 2011, and we will continue to install abatement systems, promote the reduction of the usage of PFC gas and regulate the amount of all emissions.
- Transition of amount of PFC emissions
- (The above data covers all manufacturing sites in Japan and overseas)
Reduction of greenhouse effect gases emission and effluent discharge by upcoming environmental technologies
The Semiconductor & Storage Products Company has been taking various measures to reduce environmental impact. The PFC gas abatement system introduced in Himeji Operations that drastically reduces effluent discharge is explained below.
- Introduction of a fluorine-captured PFC gas abatement system to reduce the use of water and greenhouse gas emissions
PFC gas is used in the production lines of semiconductor devices, primarily in the cleaning and etching processes. While PFC gas can have several thousand times the greenhouse effect of CO2 by volume, the Semiconductor & Storage Company Group is actively working on the reduction of the amount of the gas used and on reducing overall emissions. While the fluorine component resulting from decomposition of PFC gas is dissolved in water and processed in the case of conventional PFC gas abatement methods, the Himeji Semiconductor Plant introduced a new abatement system in 2009, which uses no water. In this system, a chemical reaction is used to capture the fluorine component as calcium fluoride (CaF2), and as a result, the emission of PFC gas has been reduced while limiting the use of water at the same time.
In addition to the system being introduced at the Himeji Semiconductor Plant, this system was also introduced at the Yokkaichi Plant in 2008. In 2010, the two plants recorded a CO2 equivalent reduction of 210,000 tons of PFC gas emissions and reduced water use by 220,000 m3.
