Spatial location of electron trapping defects on silicon by scanning tunneling microscopy

Abstract

Individual electron trapping sites in thermally oxidized silicon substrates have been observed using a scanning tunneling microscope (STM). The excellent spatial resolution of the STM allows single defects to be identified and located on the surface. The tunneling current near single trapping sites was observed to switch between two well defined values as the site occupation changed. The magnitude of the change in the current and spatial extent of the current fluctuations, typically 3 nm, is consistent with the calculated change in tunneling current from a single electron being trapped in the oxide.