Abstract
The present work is aimed at development of direct solid analysis and depth profiling using inductively coupled plasma mass spectrometry (ICP-MS) for the determination of trace elements in semiconductor materials including photoresist samples and silicon wafers. There consists of three parts in this work. Firstly, a high-throughput method involving laser ablation - inductively coupled plasma mass spectrometry (LA-ICP-MS) was developed for the determination of critical elements in the semiconductor photoresist samples. An innovative procedure was developed for preparation of artificial photoresist film standards to be used for calibration in the direct analytical process. Secondly, a dual sample introduction system of laser ablation and solution nebulization coupling to ICP-MS using on-line isotope dilution technique for the determination of boron in p-type silicon wafer was developed. The rapidly changed boron ratio is recorded by ICP-MS during analysis for subsequent quantification of the boron concentration based on isotope dilution technique. With this on-line isotope dilution method, it is possible to accurately quantify boron concentration in silicon wafer without reference to solid standard sample. Finally, a method for determination of concentration gradient of trace levels of transition metals (Cu, Zn, Cr, Co and Ni) in silicon wafer using anodic oxidation combined with microconcentric nebulizer equipped inductively coupled plasma mass spectrometry (MCN-ICP-MS) was developed. From the preliminary study on a silicon wafer polluted with trace transition metals, it indicated that a general trend showing decreasing of analyte concentration with increasing depth, in good agreement with the literature reports, was obtained. The established system of anodic oxidation combined with MCN-ICP-MS can be an effective means for the determination of concentration gradient of trace metals in silicon wafer.