Recent advanced applications of AAS and ICP-MS in the semiconductor industry

We report on instrumentation-related challenges of applying graphite furnace atomic absorption spectroscopy (GF-AAS) and inductively coupled plasma mass spectrometry (ICP-MS). We show that a significant amount of polyatomic species derived from silicon sample solution in the plasma, such as SiO, SiOH, SiOH2·SiOH3, SiO2, SiO2H, SiO2H2 and SiO2H3, can hamper the detection limits of many elements of interest. This paper describes a method for eliminating these polyatomic ions. We discuss the advantages and disadvantages of vapor phase decomposition method (VPD), drop etching method (DE) and drop sandwich-etching method (DSE) for the recovery of metal impurities from a silicon wafer surface. We report the application of the DSE method for the evaluation of near-surface metal impurities, used for gettering studies. We describe the direct acid bulk decomposition (DABD) and the room temperature acid vapor phase decomposition method (RT-AVPD) for the determination of metal impurities in bulk silicon. Finally, we report concentration of trace metal contamination in several chemical reagent solutions.