Spherical harmonics expansion of the conduction band for deterministic simulation of SiGe HBTs with full band effects

Abstract

A SiGe HBT is simulated using a deterministic Boltzmann equation solver with full band effects. An anisotropic band structure fitted to full band for high energies significantly improves the simulation of SiGe HBTs with a spherical harmonics expansion solver, especially when it comes to breakdown voltages. This makes it a more efficient alternative to stochastic Monte Carlo simulation.