Optimizing 600 V punchthrough IGBT's for unclamped inductive switching (UIS)

In this paper, we analyze the UIS capability of punchthrough (PT) IGBTs both experimentally, and through non-isothermal two-dimensional numerical simulations. It is shown that the UIS failure mechanism is determined by the open-base p-n-p structure inherent in the IGBT. By optimizing the open base p-n-p, avalanche induced second breakdown can be prevented at current densities in excess of 1000 A/cm/sup 2/. A 600 V PT-IGBT with low on-state voltage, fast switching, and >4.5 J/cm/sup 2/ UIS capability at 120 A/cm/sup 2/ is experimentally demonstrated.