Trench-IGBTs with integrated diverter structures

Improved trench-IGBT structures are proposed and discussed in this paper by introducing a p⁺-diverter region at the bottom of the trench. This improves the reliability of the device by relaxing the electrical field at the corner of the trench and diverts holes from entering the p-base region during forward conduction and, what is more important, during switching. The performed numerical analysis for structures with a diverter connected to the cathode either via a linear resistor or a p-n diode shows, that the device with a diode diverter exhibits a significant improvement of the device performance as compared with the conventional trench-IGBT. The most important result is the excellent safe operating area of the proposed device