BTI and Electron Trapping in Hf-based Dielectrics with Dual Metal Gates

In Hf-based stacks with TaC and MoNx dual metal gates, PBTI is found to be a concern. Although HfSiON reduces PBTI, worse NBTI by nitridation poses a potential issue. NBTI is also degraded by channel strain. A new pulse BTI technique is presented for electron trapping, which demonstrates the minimization of de-trapping and is used to simultaneously characterize fast and slow trapping components. Electron trapping characteristics on IL and HK thickness were also studied. It is revealed that fast trapping is from tunneling mechanism and the de-trapping behavior during stress plays important role in slow trap generation