Modeling of Bandgap Narrowing for Consistent Simulation of SiGe HBTs Across a Wide Temperature Range

We investigate the modeling of bandgap narrowing (BGN) for consistent TCAD simulation of SiGe HBTs across wide temperature ranges. At present, such consistency can only be achieved near room temperature in commercial device simulators, because of the inconsistent accounting of the temperature dependence of the Fermi-Dirac statistics correction factor to the effective bandgap. A consistent Fermi-Dirac statistics correction to the bandgap is proposed and implemented in Sentaurus (previously DESSIS) using a C++ physical modeling interface (PMI), and then compared to measured data for advanced SiGe HBTs. This new BGN correction factor leads to consistent simulation results between Boltzmann and Fermi-Dirac statistics from 77 K to 500 K. Furthermore, we explore the temperature dependence of apparent BGN by comparison of simulation and measured data.