Dynamics of threshold voltage instability in stacked high-k dielectrics: role of the interfacial oxide

In this paper, we focus on comparing the V/sub TH/-instability in scaled stacks with the trapping behavior of thick HfO/sub 2/ layers. We show that a large part of the instability is caused by charging/discharging of HfO/sub 2/ bulk defects, independent of the HfO/sub 2/ thickness. The interfacial oxide thickness influence the mechanism of charging and discharging of the HfO/sub 2/ defects.