Scanning capacitance microscopy study of carrier depletion within grains of n‐type polycrystalline silicon

Abstract

AbstractThe local electrical properties and corresponding surface topography for phosphorus‐doped n‐type polycrystalline (n‐poly) silicon layers were investigated using scanning capacitance microscopy (SCM) of chemical mechanical polishing (CMP) and backside‐etched samples. Applying negative bias stress between a sample and a scanning SCM probe tip was found to induce a depleted region within the CMP n‐ poly‐Si sample. In contrast, bias stressing does not intrinsically change the backside‐etched n‐poly‐Si sample. By combining our results with the results of energy dispersive x‐ray spectroscopy measurement, we can conclude that the active dopant concentration within n‐poly‐Si grains is inhomogeneous. Copyright © 2008 John Wiley & Sons, Ltd.