Correlation of Negative Bias Temperature Instability and Breakdown in HfO₂/TiN Gate Stacks

Abstract

Both negative bias temperature instability (NBTI) and time dependent dielectric breakdown (TDDB) are two major reliability issues for long term performance of high-k gate stacks. In this work, these two degradation mechanisms were extensively analyzed to explore any possible correlation in terms of defects formation. A variety of dielectric stacks were considered to perform NBTI and TDDB. It was observed that NBTI induced defects, generated at the interface and in the interfacial layer were somewhat identical to the defects that dominate the breakdown process.

Statistical characterization and reliability modeling of novel high-K gate dielectric stacks

“…NBTI-TDDB Interaction Study -While we focused only on the TDDB study, the NBTI / PBTI effect is also an important failure mechanism that is being extensively studied. Since both these failure mechanisms are caused by the presence of bulk and interface traps in the gate dielectric, it is necessary to understand the correlation of these two failure mechanisms and how one affects the other [325,326]. This dependency study is still in its incipient stages and requires more focus.…”