Re-dissolving vpd-txrf-droplets of 300 mm wafer for the determination of inorganic anions by capillary electrophoreis

摘要

Metallic contaminants on the surface of 300 mm wafers were routinely monitored by VPD preparation and subsequent determination with spectroscopic methods. When the scanning droplet of the VPD procedure was bisected only one wafer was required for the determination of Al and Na by ICP-MS and Cu, Fe, Ni, and Zn by TXRF. In re-dissolving the dried VPD-TXRF-droplet by 100 muL ultra pure water inorganic and organic anions could be measured using capillary electrophoresis. Although the VPD preparation resulted in a high concentration of fluoride bromide, choloride, sulfate, nitrate, oxalate and phosphate were determined down to 5centre dot10~(10) at cm~(-2).