Simultaneous measurement of potential and dopant atom distributions on wet-prepared Si(111):H surfaces by scanning tunneling microscopy

The authors demonstrate the ability of scanning tunneling microscopy and spectroscopy to simultaneously measure the distributions of both the surface potential and the individual dopant atoms on the atomically flat hydrogen-terminated Si(111) surfaces prepared by an aqueous NH4F etching without disturbing the original dopant distribution. At the p-n junctions, the acceptor and donor atoms were detected distinctly, and the variation in the observed height reflected the surface potential under the biasing condition. Further, a strong correlation between the dopant fluctuations and the surface potential distributions was identified. (c) 2007 American Institute of Physics.