Tradeoff Between Hot Carrier and Negative Bias Temperature Degradations in High-Performance $\hbox{Si}_{1 - x}\hbox{Ge}_{x}$ pMOSFETs With High-$k$/Metal Gate Stacks

Analyzed herein is the effect of different germanium (Ge) concentrations on negative bias temperature instability (NBTI) and channel hot carrier (CHC) degradations in high-performance
$\hbox{Si}_{1 - x}\hbox{Ge}_{x}$
pMOSFETs. It is shown that higher concentrations result in less NBTI degradation due to the increased barrier height between the SiGe and high-
$k$
dielectric interface, but it causes greater CHC degradation due to the decreased channel bandgap with higher Ge concentrations. Therefore, the tradeoff between NBTI and HC degradations for different Ge concentrations should be considered when developing high-performance
$ \hbox{Si}_{1 - x}\hbox{Ge}_{x}$
pMOSFETs.