Anomalous Behavior of Lateral C–V Characteristic of an MNOS Transistor with an Embedded Local Charge in the Nitride Layer

Abstract

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.