Imaging the variation in band bending across a silicon pn junction surface using spectromicroscopy

Abstract

We present a characterization of lateral silicon pn junction arrays fabricated on a Si(001) surface using a synchrotron-based scanning photoelectron microscope (SPEM). The Si 2p images show energy dependent contrast which varies continuously across the space charge region between regions of different doping. Combined with measurements of the changes in the Si 2p spectra across the pn junction, we demonstrate the capacity of SPEM in imaging variations in dopant concentration, the width of the charge depletion zone, and variations in band bending with oxide preparation.