Relating Spatially Resolved Maps of the Schottky Barrier Height to Metal/Semiconductor Interface Composition

Abstract

The Schottky barrier height (SBH) is mapped with nanoscale resolution at pure Au/Si(001) and mixed Au/Ag/Si(001) interfaces utilizing ballistic electron emission microscopy (BEEM) by acquiring and fitting spectra every 11.7 nm over a 1 micron by 1 micron area. The energetic distribution of the SBH for the mixed interfaces contain several local maximums indicative of a mixture of metal species at the interface. To estimate the composition at the interface, the distributions are fit to multiple Gaussians that account for the species, "pinch-off" effects, and defects. This electrostatic composition is compared to Rutherford backscattering spectrometry (RBS) and x-ray photo-emission spectroscopy (XPS) measurements to relate it to the physical composition at the interface.