Strained Si/SiGe MOSFET capacitance modeling based on band structure analysis

Capacitance measurements have been performed on strained Si on relaxed Si_0.8Ge_0.2 buffer and compared to self-consistent solution to Poisson-Schrodinger equations accounting for the silicon electronic band structure. The electronic structure of strained Si on Si_{1 -x}Ge_x buffer is examined using 30-level k.p analysis including spin orbit correction. The effective masses, the band gap shifts and the carrier densities are reported for various Ge concentrations. As a result, good agreement between the measurements and the simulations is obtained within the framework of our model and the impact of strained Si layer on the MOSFET capacitance is explained from accumulation to inversion regime.