A novel in-line characterization method with nanoscale lateral resolution for evaluating dry etching of InP

In this work, we demonstrate a novel application of Scanning Capacitance Microscopy (SCM) as an in-line characterization method with high lateral resolution for evaluating dry etching of semiconductors. Our SCM investigations focus on low doped n-InP surfaces dry etched with different processes. Post-etch processing, such as annealing under PH₃, for damage removal is also investigated. The SCM data suggest the formation of highly doped near surface region on as-etched samples, and a recovery of the initial electrical properties upon annealing. These conclusions are shown to be consistent with morphology information simultaneously recorded, and current-voltage (I-V) characteristics of (macroscopic) Au/InP metal-semiconductor contacts independently measured.