Field-enhanced nonequilibrium C/V and I/V characteristics of MOS capacitor under linear voltage ramp bias

A theoretical method is presented to analytically describe nonequilibrium C/V and I/V characteristics of an MOS capacitor under linear voltage ramp bias. Unlike previous theories the carrier emission probability is assumed to be field-dependent and therefore the transients are known as field enhanced. The one-dimensional Poole-Frenkel model is used to describe the carrier-emission probability dependent on the applied electric field. It has been verified that this model is available for coulombic centres. A differential equation is established to describe the change of the space-charge region width with time. The MOS capacitance and gate current are related to the space-charge region width. In this way the field enhanced nonequilibrium C/V and I/V characteristics are obtained.