Effect of strain on Negative Bias Temperature Instability of Germanium p-channel Field-Effect Transistor with high-к gate dielectric

We report the first investigation of the effect of strain on NBTI of Germanium (Ge) p-channel Field Effect Transistors (p-FETs) with high-κ gate dielectric. In this study, a mechanical wafer bending tool was used to alter strain in the Ge channel. It is found that higher longitudinal tensile strain in the channel of Ge p-FETs leads to worse NBTI performance. By reducing the tensile strain in the longitudinal direction by wafer bending, improvement in drive current and reduction of NBTI degradation are achieved. Gate width W_G dependence of NBTI in Ge p-MOSFET is also reported.