Abstract
Over the past decade, inductively coupled plasma mass spectrometry (ICP-MS) has been regarded to be one of the most powerful techniques for ultra-trace elemental analysis. This technique offers excellent analytical characteristics, (1) simplicity of spectra compared with ICP-AES, (2) extremely low detection limits (pg/ml) for most elements, (3) a broad linear dynamic range, (4) rapid multi-element determination, (5) isotope ratio and isotope dilution method capability, and (6) rapid qualitative analysis for ultra-trace metal impurities. However, even the most modern ICP-MS instruments still suffer from a number of spectral and non-spectral interferences. In order to avoid isobaric overlaps, manufacturers adopted two different concepts. One is a combination of shield-torch and chamber-gas flow for a quadrupole type MS and the other is the usage of a double-focusing high resolution (HR) mass spectrometer. Nowadays, there are ten manufacturers of ICP-MS all over the world.
In this paper, the history of development of ICP-MS is briefly reviewed at first. Applications of ICP-MS to ultra-trace elemental analysis of semiconductor materials (from water to Si wafer) are then documented, focusing the present conditions and meaning of ICP-MS analysis in this industrial field. The increase of memory capacity in the integrated circuit demands the cleanliness as high as possible for each production process. The analytical techniques of (HR-)ICP-MS including ETV is becoming an essential technology to improve their productivity.
