ABSTRACT
In this work, using InP as an example, we demonstrate the potential of scanning capacitance microscopy (SCM) as a rapid in-line evaluation tool for characterising dry-etching of semiconductors. The samples were prepared by etching low doped n-InP using different dry-etching processes. Low SCM signals (dC/dV) on as-etched surfaces are consistent with the formation of a highly doped near-surface region. Upon annealing the etched samples at 650°C under phosphine, high signals are obtained suggesting damage removal which correlates with the morphological improvements seen in the topography data. The samples were also independently characterised by current-voltage characteristics of (macroscopic) Au/InP contacts and the results confirm the SCM data.
