Effect of Bandgap Narrowing on Performance of Modern Power Devices

Abstract

The effect of the bandgap narrowing (BGN) on performance of power devices is investigated in detail in this paper. The analysis reveals that the change in the energy band structure caused by BGN can strongly affect the conductivity modulation of the bipolar devices resulting in a completely different performance. This is due to the modified injection efficiency under high-level injection conditions. Using a comprehensive analysis of the injection efficiency in a p-n junction, an analytical model for this phenomenon is developed. BGN model tuning has been proved to be essential in accurately predicting the performance of a lateral insulated-gate bipolar transistor (IGBT). Other devices such as p-i-n diodes or punch-through IGBTs are significantly affected by the BGN, while others, such as field-stop IGBTs or power MOSFETs, are only marginally affected.Index Terms-Bandgap narrowing, insulated-gate bipolar transistor (IGBT), power devices, high voltage.

Modeling of Large Area Trench IGBTs: The Effect of Birds-Beak

“…The High Field Saturation model (when the drift velocity of carriers is no longer proportional to the electric field) was instead calculated parallel to the closest semiconductor-insulator interface, which has been shown to be a more accurate model to represent the MOSFET channel behaviour [19]. The old model for Slotboom bandgap narrowing was also used since it has been shown to be more physically realistic [20]. Specific silicon parameter values based upon crystallographic lattice orientations were used, rather than the default Sentaurus general silicon values.…”