DETERMINATION OF SILICON TRACES IN PROCESS CHEMICALS FOR SEMICONDUCTOR PRODUCTION BY ETAAS

The determination of silicon in process chemicals for the IC production by electrothermal atomization atomic absorption spectrometry is described. The influence of a modifier and the possibility of multiple injections to increase the sensitivity or to improve the limit of detection were examined. The determination of silicon in H2O2 is possible without any pretreatment, HNO3, HCl, H3PO4, HClO4 and HCOOH were analysed after appropriate dilution of the concentrated acids (by a factor 2 to 10). The limits of detection (3 s of eleven blank measurements) in the measuring solution are between 0.5 and 1 ng/g. H2SO4 and organic solvents (acetone, methanol, 2-propanol, xylene, n-butyl-acetate) cannot be analysed directly or after dilution. In these cases preparation is necessary.