Accurate Dopant and Interface Characterization in Oxidized SiC with Refined Non-Contact CV Technique

The non-contact C-V technique has been recently gaining interest as a precise, cost and time effective metrology for wide-bandgap semiconductors. Originally focused on dopant measurement, non-contact C-V has been expanding to encompass wide-bandgap surface and interface characterization, including complex reliability issues critical for the future of power devices. In this work, we report progress achieved using a new direct method for determining the flatband voltage, V_FB, and capacitance, C_FB. Experimental results are presented for n-type oxidized epitaxial 4-H SiC. They demonstrate the approach and the unique self-consistent measurement producing an entire set of pertinent electrical parameters, including the interface trap density, D_it.