Characterization of Electron Traps in Gate Oxide of m-plane SiC MOS Capacitors

The electron trapping in gate oxides of SiC-MOS capacitors were studied by electron injection from the substrate. The trapped electron densities calculated using the flat-band voltage shift were analyzed. There are possibly three types of electron traps. Their capture cross sections are >2x10
^-13
cm
²
, ~3x10
^-14
cm
²
and <3x10
^-18
cm
²
. The oxide grown by LPCVD has slightly lower electron trap density than the oxides by thermal oxidation or by TEOS-PECVD with regard to the oxide trap with capture cross section of 3x10
^-14
cm
²
. Yet the obtained electron trap densities were found to be one order of magnitude higher than that of Si-MOS [4] and there may be large room for improvement of the electron trap in the gate oxide of SiC-MOSFET for better VT reliability.