7.5. Interface trap level density (Dit)

These are positive or negative charges, due to structural defects, oxidation-induced defects, metal impurities, or other defects caused by radiation or similar bond breaking processes (*e.g.*, hot electrons). The interface trapped charge is located at the SiC–SiO2 interface. Unlike the fixed \$.#!z+.z0.,,! z\$.#!\_z%\*0!."!z0.,,! z\$.#!z%/z%\*z!(!0.%(z+))1\*%0%+\*z3%0\$z0\$!z1\*¥ !.(5%\*#z%^z \*0!."!z0.,/z\*z!z\$.#! z+.z %/\$.#! \_z !,!\* %\*#z+\*z0\$!z/1."!z,+0!\*¥ tial.This charge type has been also called surface states, fast statesand interface states and so on.

There are three main approaches to investigate the problem of interface state.


 \*0!."!z0.,z\$\*#!z0\$!%.z\$.#!/z/0!z !,!\* %\*#z+\*z3\$!0\$!.z0\$!5z.!z"%((! z+.z!),05^z¥ !,0+.z%\*0!."!z0.,/z.!z\*!#0%2!z3\$!\*z"%((! \_z\* z\*!10.(z3\$!\*z!),05\_z3\$!.!/z +\*+.z%\*¥ terface traps are neutral when filled and positive when empty. Both types of interface traps may exist, perhaps simultaneously in the same device.

$$D\_{it} = \frac{1}{q} \left[ \left\{ \frac{1}{\mathcal{C}\_{LF}} - \frac{1}{\mathcal{C}\_{out}} \right\}^{-1} - \left\{ \frac{1}{\mathcal{C}\_{HF}} - \frac{1}{\mathcal{C}\_{out}} \right\}^{-1} \right] \tag{13}$$
