Review of LCA methods for ICT products and the impact of high purity and high cost materials

Abstract

This paper expands upon previously published work aimed at more fully assessing the lifecycle impacts of semiconductor manufacturing and product use. Specific focus is placed on energy and CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> impacts associated with bringing materials to the high purity grade required for semiconductor manufacturing. Past studies have suggested that high purity materials account for a significant portion of the lifecycle CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> impact of electronic products generally, and semiconductor products in particular. Although most high purity materials have a very high cost and obviously require more energy for additional purification, it is not accurate to assume that there is a linear correlation between chemical cost and energy intensity. While this relationship may hold for many commodity chemicals, it is likely to be less accurate for the specialty chemicals and materials used in semiconductor and electronic products. Other factors such as research and development costs or competitive advantages gained through intellectual property are more significant contributors to high input material costs. The authors performed a detailed study of the additional purification steps needed for many of the key chemicals used in semiconductor manufacturing. Results will be presented that estimate the total contribution of high purity materials to the overall semiconductor energy and CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> impact. The authors believe this information will be useful for future life cycle assessments for the semiconductor and ICT industries as it offers more accurate life cycle assessment data for chemicals and gases used for semiconductor manufacturing. By presenting more accurate data, the authors hope this will help identify areas of opportunity for energy and CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> reduction. Additional recommendations will also be provided to assist future LCA work.