Studying atomic scale structural and electronic properties of ion implanted silicon samples using cross-sectional scanning tunneling microscopy

Abstract

The atomic scale structural and electronic characteristics of a silicon sample implanted with bismuth atoms are investigated using cross-sectional scanning tunneling microscopy (XSTM) and scanning tunneling spectroscopy (STS). We demonstrate that cleaving ion implanted samples provides an effective room temperature route for the preparation of atomically flat silicon surfaces with low defect density, preventing the diffusion of volatile impurities such as dopants. This enables atomic resolution STM studies of solitary implanted impurity atoms in their intrinsic silicon crystal sites and further allows us to map out a depth profile of the band-structure of the implanted area using STS.