A study of negative-bias temperature instability of SOI and body-tied FinFETs

Negative-bias temperature-instability (NBTI) characteristics are carefully studied on SOI and body-tied pMOS FinFETs for the first time. It was observed that a narrow fin width degraded device lifetime more than a wider fin width. Electrons generated by the NBT stress are accumulated at the center of a silicon fin and cause energy-band bending. This results in an incremental hole population at the interface. The energy band is bent more steeply at the narrow fin than at the wide fin by the accumulated electrons. A body-tied FinFET shows better immunity to NBT stress due to a substrate contact.