Comparison of Charge Pumping and $1/f$ Noise in Irradiated Ge pMOSFETs

Irradiated Ge pMOSFETs have been characterized via charge pumping (ICP) and 1/fnoise. The noise increases much more with irradiation than doesICPfor devices with eight Si monolayers at the interface, while devices with five Si monolayers and lower halo implantation dose exhibit comparable increases in noise andICPwith irradiation. These results suggest that border traps in the HfO2affect the noise more than interface traps, and that devices with eight Si monolayers have a higher border-trap density than devices with five Si monolayers. Noise measurements as a function of gate voltage show that the border trap density increases significantly toward the Ge valence band edge, while three-level charge pumping reveals an interface trap density that increases slightly toward midgap.