Extraction of slow oxide trap concentration profiles in metal-oxide-semiconductor transistors using the charge pumping method

The charge pumping technique is shown to be a very efficient method for studying the slow traps in the oxide of metal-oxide-semiconductor (MOS) transistors. The trap concentration is obtained by varying the gate pulse frequency, the other measurement parameters being kept constant. The concentrations measured on virgin devices are in agreement with those generally obtained on state-of-the-art MOS transistors using noise measurements. On virgin and stressed devices, they also agree with those measured using a drain current transient technique. The concentration profiles show an increase of the trap density near the oxide-semiconductor interface. (C) 1996 American Institute of Physics.