Actions of negative bias temperature instability (NBTI) and hot carriers in ultra-deep submicron p-channel metal-oxide-semiconductor field-effect transistors (PMOSFETs)

摘要

Hot carrier injection (HCI) at high temperatures and different values of gate bias V_g has been performed in order to study the actions of negative bias temperature instability (NBTI) and hot carriers. Hot-carrier-stress-induced damage at V_g = V_d, where V_d is the voltage of the transistor drain, increases as temperature rises, contrary to conventional hot carrier behaviour, which is identified as being related to the NBTI. A comparison between the actions of NBTI and hot carriers at low and high gate voltages shows that the damage behaviours are quite different: the low gate voltage stress results in an increase in transconductance, while the NBTI-dominated high gate voltage and high temperature stress causes a decrease in transconductance. It is concluded that this can be a major source of hot carrier damage at elevated temperatures and high gate voltage stressing of p-channel metal-oxide-semiconductor field-effect transistors (PMOSFETs). We demonstrate a novel mode of NBTI-enhanced hot carrier degradation in PMOSFETs. A novel method to decouple the actions of NBTI from that of hot carriers is also presented.