Electromechanical characterization of “flying” Planar Gate Punch Through IGBT bare die

Abstract

The effect of mechanical stress on the power dice is investigated by considering the application of mechanical stress on a Punch Through Planar Insulated Gate Bipolar Transistor under static electrical characterizations. Specific test vehicles and test bench for applying a tensile or compressive mechanical stress are described in detail. Furthermore, 2D finite element simulations are carried out to understand the device behavior by internal physics analysis. The impact of the mechanical stress cannot be neglected. Indeed, the results show a similar tendency between simulations and experiments for two static electrical characterizations: the output characteristics are sensitive to mechanical stress whereas the effect is negligible on the breakdown voltage. The case of the threshold voltage shows a disparity between experiments and simulations. Globally, such silicon property might be a key point to propose a real-time monitoring of the mechanical state evolution of the power assemblies.