Modeling and validation of piezoresistive coefficients in Si hole inversion layers

The piezoresistive coefficient extraction technique for hole inversion layers based on the linear response of the mobility to uniaxial stress is generalized for material of the general diamond crystal type. The new derivation is applicable for arbitrary surface and channel orientations. For the simulation of piezoresistive coefficients, a mobility model for hole inversion layers based on the self-consistent solution of the 6×6k→·p→ Schrödinger equation (SE), Boltzmann transport equation (BTE) and Poisson equation (PE) has been developed. Mobility variations due to uniaxial stress and biaxial strain are simulated and the simulation results reproduce available measurements. The accuracy of the piezoresistivity model, which describes the linear response and is based on the extracted piezoresistive coefficients, is examined by comparing the mobility variations resulting from the k→·p→ simulator with the model predictions for many configurations of stress/strain and surface/channel orientation.