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

We present a characterization of lateral silicon pn junction arrays fabrica ted on a Si(001) surface using a synchrotron-based scanning photoelectron m icroscope (SPEM). The Si 2p images show energy dependent contrast which var ies continuously across the space charge region between regions of differen t doping. Combined with measurements of the changes in the Si 2p spectra ac ross the pn junction, we demonstrate the capacity of SPEM in imaging variat ions in dopant concentration, the width of the charge depletion zone, and v ariations in band bending with oxide preparation. (C) 2000 American Institu te of Physics. [S0021-8979(00)00814-8].