High-Field Electron Mobility Model for Strained-Silicon Devices

摘要

The application of mechanical stress to enhance the carrier mobility in silicon has been well established in the last few years. This paper probes into the electron conduction in biaxially and uniaxially stressed silicon in the nonlinear transport regime. The electron behavior has been analyzed for different field directions and stress/strain conditions using full-band Monte Carlo simulations. An analytical model describing the velocity components parallel and perpendicular to the electric field has been developed. The model includes the effect of strain induced valley splitting and can be applied for arbitrary directions of the electric field. The extension to different field directions has been performed using a Fourier series interpolation and a spherical harmonics interpolation for transport in two and three dimensions, respectively. The model can be implemented in a drift-diffusion-based device simulator.