Optically Assisted Charge Pumping on Floating-Body FETs

An optical charge-pumping (CP) method is proposed to extract the interface trap density in floating-body (FB) field-effect transistors (FETs). Optically generated majority carriers are removed from the FB by applying a burst of charge-pumping pulses to the gate. The change of the drain current after each CP pulse is used to determine the interface trap density. The advantage of this method lies in the possibility to characterize FB FETs without the unnecessary generation of interface traps by measurement bias. In addition, it can be applied to various types of FB devices directly without structural modification.