Physical-Based Threshold Voltage and Mobility Models Including Shallow Trench Isolation Stress Effect on nMOSFETs

Physical-based threshold voltage and channel mobility models to include shallow trench isolation (STI) mechanical stress effects on MOSFET I–V characteristics were described. The parameter Δs, meaning the change along the MOSFET channel length under STI stress,
$\Delta E_{eceg}$
,
$\Delta E_{dos}$
, and
$\Delta E_m$
, meaning the activation energy per strain due to STI stress are used in models.
$\Delta E_{eceg}$
describes the STI-stress-induced electron affinity, band-gap narrowing effects.
$\Delta E_{dos}$
describes density-of-states changes due to the light and heavy hole mass changes under STI stress, and
$\Delta E_m$
corresponds to the STI-stress-induced mobility changes. The STI stress induced tens of millivolts shifts in threshold voltage, and 40% shift in channel mobility on nano-MOSFET region. The models are verified by the 130-nm technology nMOSFET-layout-dependent experiment data including various gate length, active area, and gate location.