Semiconductor lithography process
TSMC actively participates in seminars on hazardous substance management, identifies the latest trends, and leads the effort on related projects
CASE STUDY

TSMC Replaces Perfluorooctanoic Acid Related Substances

Minglien Lo
2018/10/19

As a provider of the most comprehensive technologies and services in the field of integrated circuit manufacturing, TSMC is committed to developing innovative and environmentally sustainable products for its customers. TSMC also lists hazardous substance management as part of its long-term strategies and sustainability goals. In order to anticipate and respond to global trends in environmental regulations, TSMC’s Corporate Environment, Safety and Health Division is actively involved in the Environment, Safety and Health Committee (ESH) of the World Semiconductor Council (WSC). In recent years, TSMC has noted the long chain Perfluoroalkyl Substances (PFAS), especially Perfluorooctanoic Acid (PFOA), and its related substances may cause to human health and the environment. Therefore, TSMC is actively promoting the PFOA related substances replacement program and has successfully completed the verification of all replacement chemicals in the second quarter of 2018. All PFOA related substances are expected to be replaced by the end of the year.

Introduction and Application of Perfluoroalkyl Substances

Introduction

  • PFAS can be roughly divided into two categories: long-chain (eight carbon atoms or more) and short chain (less than eight carbon atoms).
  • Long-chain PFAS include Perfluorooctane Sulphonate (PFOS), Perfluorooctanoic Acid (PFOA), and related substances
  • Applications

  • Daily commodities
    Pizza boxes, microwave popcorn bags and other oil-proof paper bags, textiles, carpets, shoe materials, aviation technology, transportation, electronics, and kitchenware.
  • Semiconductors
    Photolithography processes, including Photoacid Generators (PAGs) and Anti-reflective Coatings (ARCs).
  • Proactive Management of Hazardous Substances

    At present, many countries in the world, including Taiwan, have legislations to control PFOS, PFOA and related substances. TSMC has also been taking precautionary actions.

    Replacement Material Assessments Are Performed beyond Standard Regulatory Requirements

    The replacement chemicals used by TSMC are all short-chain (four carbon atoms or less) PFAS substances, which pose no significant harm to the human body or the environment. A safety mechanism has also been established in the green procurement procedure which lists and bans the use of long-chain PFAS-containing materials. Banned substances are excluded from new material assessments. Although no research findings have shown that PFAS with five, six or seven carbon atoms are causing bodily harm or environmental damage, and government regulations for these substances are to be clarified, TSMC still maintains the principle of “Do not use unless necessary“ in the management of lower-risk substances. If such substances must be used in response to the development of new processes, their usage not only needs to fully comply with regulatory requirements for hazardous chemicals, but also follow TSMC internal procedures, and a usage application may need to be approved by vice-president level or above personnel.

    In the management of hazardous substances, TSMC maintains a cautious attitude. In addition to striving for the goal of not using PFOA-containing materials by the end of 2018, TSMC will continue to study PFAS-related research and regulations in order to be updated on the latest sustainability trends.