Understanding Strain Effects on Double-Gate FinFET Drive-Current Enhancement, Hot-Carrier Reliability and Ring-Oscillator Delay Performance via Uniaxial Wafer Bending Experiments

Strain induced drive current enhancement on double-gate (DG) FinFETs from contact etch stop liners (CESLs) is modeled by performing wafer bending experiments. Longitudinal piezoresistance co-efficients for DG - FinFETs are extracted and shown to be different from the bulk Si values. This understanding is further used to gain insight into strain effects on FinFET ring-oscillator (RO) delay performance. FinFET hot- carrier degradation is observed to be enhanced for both tension and compression, and is explained to be due to increased impact- ionization from strain induced bandgap narrowing at the drain- body junction.