Test Method and Specification for Testing Perfluoroalkoxy (PFA) Materials Used in Liquid Chemical Distribution Systems
Aggressive chemicals such as hydrochloric, hydrofluoric and nitric acid are known to leach metals from polymer piping. PFA with low extraction is critical when manufacturing leading-edge semiconductors. SEMI C90 establishes extraction requirements for PFA material and components used in chemical distribution systems and process tools.
Components are extracted for 24 hours in 5% nitric acid. Following exposure, the extract is analyzed for trace metal concentration using Inductively Coupled Plasma – Mass Spectroscopy (ICP/MS). Using the volume of the extract and surface area of the component under test, an area normalized extraction mass is calculated and compared to the current criteria. Tubing, pipe, valves and most fluid handling components can be evaluated for acid extractables using SEMI C90.