First results of TXRF measurements of low-Z elements on Si wafer surfaces at the PTB plane grating monochromator beamline for undulator radiation at BESSY II

First measurements of low-Z elements on Si wafer surfaces with undulator an d wiggler radiation excited total reflection x-ray fluorescence (TXRF) spec trometry were performed at the PTB plane grating monochromator beamline for undulator radiation at the electron storage ring BESSY II. The synchrotron radiation (SR) TXRF spectrometer for low-Z elements of the Atominstitut wa s used, equipped with a down-looking Ge(HP) detector with a 300 nm NORWAR w indow, with the wafer positioned horizontally. Experiments were performed w ith excitation energies above 0.7 keV in the wiggler mode and with excitati on energies below 0.7 keV in the undulator mode of the PTB insertion device U180. For droplet samples on Si wafer surfaces detection limits for Na dow n to C were found to be in the low-picogram range. Copyright (C) 2001 John Wiley & Sons, Ltd.