IGBT field-stop design for good short circuit ruggedness and a better trade-off with respect to static and dynamic switching characteristics

The doping profile of the field-stop zone influences the static characteristics (Vce, sat, Vbr) and the dynamic switching characteristics (dic/dt, dVCE/dt, softness) of IGBTs. Furthermore, the short-circuit ruggedness is strongly influenced by the rear side structure of the IGET. In this work, box-like field-stop profiles in combination with a constant p-emitter were analyzed by TCAD simulations. The findings were used to optimize and realize field-stop profiles by proton implantation with the focus to achieve an improved short-circuit ruggedness at the same softness.