Characterization of surface mobility on the sidewalls of dry-etched trenches

The mobility on the sidewalls of the etched trenches was measured for electrons and holes for two surface orientation, for two different trench etch processes, and for various post-etch treatments. It was found that the dry etch process decreases the mobility of electrons for both processors and orientations and for all post-etch treatments. However, hole mobility is not reduced significantly by the dry etch processes. It is proposed that atomic scale surface roughness is the cause of the electron mobility reduction. Holes seem to be more immune to these surface roughness effects; thus the mobility is not significantly reduced by the dry etch process. Moreover, because of quantization and effective mass considerations, the hole mobility on