1991 Volume 7 Issue Supple Pages 1265-1268
Chloride ion and several metals in submicron VLSI grade photoresists have been determined at their trace levels. Chloride ion was determined by potentiometric argentometric titration of standard silver nitrate solution in acetone. Good recovery was obtained for as low as 2μg of total chloride, including those attributed to blank and sample, in the titration cell. In the determination of trace metals, we made comparison between two methods, namely, flame AAS preceded by dry ashing of the photoresist and the direct analysis using graphite furnace AAS without sample digestion. In the latter method, oxygen ashing was employed. Analytical results for iron and zinc by the two methods were comparable.