Differential Variable Base Charge Pumping ($\Delta-\text{CP}$) for SiO2/SiC Interface Characterization

We propose an electrical evaluation technique named differential charge pumping (Δ-CP) to extract information on the interface states (D
_it
) at the SiC/SiO
₂
interface. This technique allows to obtain information on (1) the physical location of the D
_it
; (2) the energetic spread of the D
_it
in the bandgap; (3) if the D
_it
are donor or acceptor type. First results indicate contributions from both the “S/D” region and the channel regions to the overall CP signal. Surprisingly a substantial contribution of the “S/D” regions of the transistors to the overall CP signal is observed. In the channel region, both donors and acceptor type states are identified, the majority being acceptor type.