We have grown homoepitaxial high resistivity SiC layers on conducting SiC substrates. We develop a method to determine the thickness of grown layers by scanning confocal Raman spectroscopy (SCRS).
We also grow epitaxial graphene on SiC layers to label the top sample surface, and, we correlate the top surface position with Rayleigh scattering (RS). The interface between the high resistivity SiC layer and conductive SiC substrate is probed by the transition from LO phonon to the coupled LO phonon-plasmon Raman mode.
The layer thickness measurements are verified by ellipsometry and Secondary Ion Mass Spectroscopy (SIMS). We show that the SCRS method provides superior lateral and vertical resolution, it is robust against errorneous conclusions based on ad-hoc models, and it is easy to implement. (C) 2019 Elsevier B.V.
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