On the ‘permanent’ component of NBTI

A number of recent publications explain NBTI to be due to a recoverable and a more permanent component. While a lot of information has been gathered on the recoverable component, the permanent component has been somewhat elusive. We demonstrate that oxide defects commonly linked to the recoverable component also form an important contribution to the permanent component of NBTI. As such, they can contribute to both the threshold voltage shift as well as the charge pumping current. Under favorable conditions, the permanent component can show recovery rates comparable to that of the recoverable component.