Anomalous behavior of lateral $C$–$V$ characteristic of an MNOS transistor with an embedded local charge in the nitride layer

The $C$–$V$ characteristic of the lateral source–substrate junction in a metal–nitride–oxide–semiconductor transistor has been simulated. With a certain voltage across the junction that depends on the dopant concentration in the substrate, a local trapped charge embedded in the nitride layer causes an anomalous rise or fall of the junction capacitance. Such a capacitance variation is associated with charge carrier redistribution in the near-surface region of the substrate when the trapped charge is embedded. This feature of the $C$–$V$ characteristic can be used to detect a local charge embedded in the insulating layer of a field-effect transistor.