AN119: Determination of an Anionic Fluorochemical Surfactant in a Semiconductor Etch Bath

Instrument Type: IC

This AN describes the techniques, instrumentation, and method for determining low mg/L (ppm) amounts of the fluorochemical surfactant FC-93 in an etch bath (1 part hydrofluoric acid/6 parts ammonium fluoride) by IC. The surfactant is removed from the HF matrix by passing the sample through an IonPac NG1 column. The IonPac NG1 is a polymeric, reversed-phase column that quantitatively retains the surfactant but does not retain inorganic anions. The concentrated surfactant is then eluted from the IonPac NG1 onto an OmniPac PAX-500 column set and detected by chemically-suppressed conductivity.