Total reflection X-ray fluorescence spectroscopy using synchrotron radiation for trace impurity analysis of silicon wafer surfaces

One of the principal industry standard means of measuring surface and near surface wafer contamination is the total reflection X-ray fluorescence (TXRF). A TXRF experiment using synchrotron radiation is carried out at the Advance light source (ALS) beamline 10.32 to investigate the performance of synchrotron radiation based approaches for this application. The detection limit of 4.9×109 atoms/cm2 is achievable for the 3-d elements with the present ALS TXRF beamline 10.32. This is due to the greatly improved signal to background in case of the synchrotron radiation TXRF. Furthermore, there is a path to improving the synchrotron case to reach a detection limit of 7.8 × 107 atoms/cm2.