Reliable extraction of interface states from charge pumping method in ultra-thin gate oxide MOSFETs

The accuracy and validity of charge pumping (CP) method is questionable in ultra-thin gate oxide MOSFETs due to the increase of the direct tunneling, currents at low gate biases. A gate pulsing window for the CP technique is proposed to reduce the influence of this parasitic leakage Current effect. Within the window, the CP method is still an excellent tool to measure the average interface trap density. Moreover, the range of this window strongly depends on the gate oxide thickness, the channel length and the gate pulsing frequency.