Increased regulatory scrutiny of photolithography chemistries: the need for science and innovation (Conference Presentation)

Semiconductor fabrication processes have evolved enormously with time, largely driven by the demand for advanced device architectures and increased performance. To continue to drive innovation and to achieve the desired electrical functionality required by today’s market, the industry relies on a number of highly sophisticated chemicals and materials. The semiconductor industry has traditionally adopted risk-based programs to reduce exposure potentials and environmental emissions or found safer alternatives when possible. For example, the industry was successfully able to phase out the use of perfluorooctanyl sulfonates (PFOS) and was able to surpass its 10-year goal in reducing the emissions of perfluorocompound (PFC) gases from semiconductor fabs. These two examples highlight recent voluntary initiatives undertaken by the industry to ensure the continued safe and responsible use of chemicals in semiconductor manufacturing processes. In June 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act was signed into law significantly amending the Toxic Substances Control Act (TSCA) which is the main chemical safety law in the United States. TSCA has a broad scope and applies to the full life cycle of a chemical substance (i.e., manufacturing, processing, use, and disposal). Since TSCA reform the process as well as the data required to bring new chemicals to the market has changed dramatically. Therefore, chemical issues which have historically been managed singularly between the EPA and a specific company may be more effectively dealt with through industry-wide consortiums, including both chemical manufacturers and users. Consortiums of this nature are likely better positioned to generate data and information relevant to the entire life cycle of a chemical. For example, EPA recently denied low volume exemption requests (LVEs) for photoacid generators (PAGs) due to increased concerns regarding the environmental, health, and safety aspects of onium–based compounds. To address EPA’s concerns, a "PAG onium" consortium was formed to fill critical data gaps throughout the life cycle of these chemicals that will allow for a more accurate assessment of the potential risks associated with the use of these chemistries. Other photolithography chemistries that are under an increased level of scrutiny include short chain perfluorinated compounds (e.g., perfluorobutanesulfonic acid derivatives) and N-Methyl-2-pyrrolidone (NMP). This talk will discuss how recent changes to the regulatory landscape have changed EPA’s chemical reviews and the resulting implications on the information/ data required to evaluate a chemical before bringing it to market.