A Physically-Based Analytic Model for Stress-Induced Hole Mobility Enhancement

A new, computationally efficient model for silicon hole mobility under stress is presented. The model predicts the modulation of hole mobility by stress under arbitrary stress conditions, channel orientations, and fields. The model uses a simplified k-space description of the silicon valence band, while preserving the relevant symmetry properties. The shape of the bandstructure is a function of the shear and biaxial stress components in the crystal coordinates, and the mobility tensor is computed for the given stress conditions. The model is based on the results of a rigorous silicon valence bandstructure calculation, and is calibrated and tested using extensive wafer-bending data.