In this paper, a comprehensive study of hot-carrier injection (HCI) has been performed on high-performance Si-passivated pMOSFETs with high-k metal gate fabricated on k-type germanium-on-silicon (Ge-on-Si) substrates. Negative bias temperature instability (NBTI) has also been explored on the same devices. The following are found: 1) Impact ionization rate in Ge-on-Si MOSFETs is approximately two orders higher as compared to their Si counterpart; 2) NBTI degradation is a lesser concern than HCI for Ge-on-Si pMOSFETs; and 3) increasing the Si-passivation thickness from four to eight monolayers provides a remarkable lifetime improvement. © 2009 IEEE.
- Hot carrier (HC)
- Impact ionization
- Negative bias temperature instability (NBTI)