Analysis and compact modeling of a vertical grounded-base n-p-n bipolar transistor used as ESD protection in a smart power technology

A thorough analysis of the physical mechanisms involved in a vertical grounded-base n-p-n bipolar transistor (VGBNPN) under electrostatic discharge (ESD) stress is first carried out by using two-dimensional (2-D) device simulation, transmission line pulse measurement (TLP) and photoemission experiments. This analysis is used to account for the unexpected low value of the VGBNPN snapback holding voltage under TLP stress. A compact model based on a new avalanche formulation resulting from the exact resolution of the ionization integral is therefore proposed.