MAPPING ELECTRICALLY ACTIVE DOPANT PROFILES BY FIELD-EMISSION SCANNING ELECTRON-MICROSCOPY

Secondary electron (SE) image contrast from p-type silicon has been st udied using field-emission scanning electron microscopy (FE-SEM). Cros s-sectional FE-SEM images of boron-doped silicon heterostructures have been compared with atomic concentration and free carrier profiles mea sured by secondary-ion mass spectroscopy and electrochemical capacitan ce-voltage profiling, respectively. FE-SEM image contrast due to dopan ts has been shown to be electronic in origin. Since electrically activ e dopant species contribute solely to SE image contrast, FE-SEM can be effectively used to map electrically active dopant profiles in two di mensions with a sensitivity as low as 10(16) cm(-3). (C) 1996 American Institute of Physics.