Direct atomic scale characterization of interfaces and doping layers in field-effect transistors

Abstract

Atomic-resolution Z-contrast imaging and electron energy loss spectroscopy combined with energy dispersive x-ray spectroscopy are used to investigate the structure-property relationships in an ideal metal–oxide–semiconductor device structure. Arsenic segregation with a very narrow profile occurring precisely at the silicide/Si interface was identified. Images show that the As is substitutional on the Si lattice sites, implying that it remains electrically active. These structural results imply desirable electronic properties for the device and are consistent with electrical measurements showing a decrease in contact resistance for these samples.