ACCURACY OF TOTAL-REFLECTION X-RAY-FLUORESCENCE SPECTROMETRY NEAR THEDETECTION LIMIT

Total reflection X-ray fluorescence spectrometry (TXRF) is one of the most common tools to analyze metal contaminants on silicon wafers and other substrate surfaces. Although the detection limit of commercial T XRF was improved to the concentration region of 10(9) atoms cm(-2), it s accuracy at low concentration was not yet clarified until now. In th is paper, we examine the accuracy of the quantitative analysis by TXRF under 10(11) atoms cm(-2) for Fe, Ni, Cu and Zn. In particular, four factors (standard sample, reference analyzing method, compensation of spurious peak and peak separation) are considered. Under a controlled condition, the accuracy is within 20% as compared with atomic absorpti on spectrophotometry (AAS).