Materials Science and Engineering | Physics | Semiconductor and Optical Materials
We calibrate the secondary electron signal from a standard scanning electron microscope to voltage, yielding an image of the surface or near-surface potential. Data on both atomically abrupt heterojunction GaInP/GaAs and diffused homojunction Si solar cell devices clearly show the expected variation in potential with position and applied bias, giving depletion widths and locating metallurgical junctions to an accuracy better than 10 nm. In some images, distortion near the p-n junction is observed, seemingly consistent with the effects of lateral electric fields (patch fields). Reducing the tube bias removes this distortion. This approach results in rapid and straightforward collection of near-surface potential data using a standard scanning electron microscope.
Copyright © 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Journal of Applied Physics, 2012, volume 111, issue 4 and may be found at doi:10.1063/1.3684556
Jennifer T. Heath, Chun-Sheng Jiang, & Mowafak M. Al-Jassim
Measurement of semiconductor surface potential using the scanning electron microscope.
Journal of Applied Physics, 2012, volume 111, issue 4
Heath, Jennifer T.; Jiang, Chun-Sheng; and Al-Jassim, Mowafak M., "Measurement of Semiconductor Surface Potential Using the Scanning Electron Microscope" (2012). Faculty Publications. Published Version. Submission 3.