Abstract
A method has been developed based on an on-line isotope dilution technique couple with laser ablation/inductively coupled plasma mass spectrometry (LA-ICP-MS), for the determination of boron in p-type silicon wafers. The laser-ablated sample aerosol was mixed on-line with an enriched boron aerosol supplied continuously using a conventional nebulization system. Upon mixing the two aerosol streams, the isotope ratio of boron changed rapidly and was then recorded by the ICP-MS system for subsequent quantification based on the isotope dilution principle. As an on-line solid analysis method, this system accurately quantifies boron concentrations in silicon wafers without the need for an internal or external solid reference standard material. Using this on-line isotope dilution technique, the limit of detection for boron in silicon wafers is 2.8 × 10 15 atoms cm -3 . The analytical results obtained using this on-line methodology agree well with those obtained using wet chemical digestion methods for the analysis of p-type silicon wafers containing boron concentrations ranging from 1.0 × 10 16 to 9.6 × 10 18 atoms cm -3 . © 2009 Elsevier B.V. All rights reserved.