A general model for interface-trap charge-pumping effects in MOS devices

Abstract

Abstract Interface-trap charge-pumping effect is analysed on the basis of Shockley-Read-Hall theory of trapping, and a model describing the effect for any trapezoidal gate waveform and any reverse biasing source voltage is derived. A simplified version of the model which is valid for identical rise and fall times is also presented and experimentally verified. Experimental results indicate that the spatial variation of surface potential and the modulation of effective gate area by source voltage may strongly influence the charge-pumping current. It is also shown that the effect of gate-area modulation can be characterized directly from charge-pumping measurements.