Chemical mechanical planarization (CMP) levels wafer surfaces before vapor deposition and subsequent processing steps. The working fluid is a slurry of fine abrasive particles, chemicals and water. In CMP, components made with DuPont™ Teflon® help guard against contamination of process fluids and slurries that come in contact with wafers.
For slurries and DI water, piping of highly pure Teflon® PFA HP helps prevent the introduction of contaminants. Piping can be joined by thermal welding or with flare-type connections. Teflon® PFA HP is compatible with chemically aggressive DI water used for dilution and washing.
Valves, fittings and pumps with all wetted surfaces made from Teflon® PFA HP or Teflon® PTFE provide a high level of protection against contamination.
Sensors and Flowmeters
Flowmeters indicate fluid flow rates. Capacitive-type sensors shielded in dip tubes of high-purity Teflon® PFA HP monitor fluid levels in tanks. Other designs can sense through walls of tanks or pipe made from Teflon® PFA HP. Connecting cables are jacketed with Teflon® PFA for additional protection against contamination.