Gate C-V characteristics of Si MOSFETs with uniaxial strain along 〈110〉 direction

Gate C-V characteristics of nMOSFETs fabricated on 100 silicon and subjected to a uniaxial strain applied along the <110> direction are studied. MOS electrostatics is calculated by solving self-consistent Schrodinger-Poisson equations including wave-function penetration into the gate dielectrics. It is observed that the gate capacitance increases in strong inversion with strain, but is relatively unaffected by strain in depletion region. This is due to the changes in the electron quantization mass and density of states effective mass with strain. We have also found that the effect of strain on the gate capacitance is not sensitive to changes in the substrate doping density.