Ultrathin High-k Films Research Articles

Nanoscale imaging and X-ray spectroscopy of electrically active defects in ultra thin dielectrics on silicon

This work concerns deeply bound charge centers in ultra thin high-k films. Non-contact Atomic Force Microscopy was used to simultaneously image topology and electric force data arising from unscreened fixed charges. These charges were produced using synchrotron radiation to pump Si L and K shell transitions. Defect charging then results from electron transfer between a defect state and a core hole state. We were able to demonstrate the local detection of x-ray absorption spectra using the probe tip. This enabled us to establish a possible link between film morphology, electronic defects and local stoichiometry in ultra thin high-k films on the nm scale.