  Strain is commonly used in metal-oxide-semiconductor technologies to boost
on-state performance. This booster has been in production for at least a
decade. Despite this, a systematic study of the impact of strain on off-state
leakage current has been lacking. In this work we use experimental data and
ab-initio calculations to refine existing models to account for the impact of
strain on band-to-band tunnelling and trap-assisted tunnelling in silicon. We
observe that the strain may dramatically increase the leakage current,
depending on the type of tunnelling involved. For band-to-band and
trap-assisted tunnelling, low uniaxial strains of 0.1% (or 180 MPa) can
increase the leakage current by 60% and 10% compared to the unstrained case,
respectively. Using our models, we predict that compressive strain on the order
of 1% (or 2 GPa) can increase the leakage current by 150 times. Conversely,
tensile strain may diminish or at most double the leakage current in all
observed cases. Though detrimental in conventional inversion-mode MOSFETs,
these processes may be used to boost the performance of Tunnel Field Effect
Transistors, where on-state current is defined by band-to-band tunnelling.
