Nanoscale mapping of the W/Si(001) Schottky barrier.
- Resource Type
- Article
- Authors
- Durcan, Chris A.; Balsano, Robert; LaBella, Vincent P.
- Source
- Journal of Applied Physics. 2014, Vol. 116 Issue 2, p023705-1-023705-7. 7p. 6 Graphs.
- Subject
- *NANOSTRUCTURED materials
*SCHOTTKY barrier diodes
*BAND gaps
*SEMICONDUCTOR-metal boundaries
*SEMICONDUCTOR diodes
*BACKSCATTERING
*SILICON
- Language
- ISSN
- 0021-8979
The W/Si(001) Schottky barrier was spatially mapped with nanoscale resolution using ballistic electron emission microscopy (BEEM) and ballistic hole emission microscopy (BHEM) using n-type and p-type silicon substrates. The formation of an interfacial tungsten silicide is observed utilizing transmission electron microscopy and Rutherford backscattering spectrometry. The BEEM and BHEM spectra are fit utilizing a linearization method based on the power law BEEM model using the Prietsch Ludeke fitting exponent. The aggregate of the Schottky barrier heights from n-type (0.71 eV) and p-type (0.47 eV) silicon agrees with the silicon band gap at 80 K. Spatially resolved maps of the Schottky barrier are generated from grids of 7225 spectra taken over a 1 μm ×1 μm area and provide insight into its homogeneity. Histograms of the barrier heights have a Gaussian component consistent with an interface dipole model and show deviations that are localized in the spatial maps and are attributed to compositional fluctuations, nanoscale defects, and foreign materials. [ABSTRACT FROM AUTHOR]