Design and Fabrication of FS-IGBTs With Enhanced Ruggedness and the Influence of Circuit Parameters on Short-Circuit

Field-Stop Insulated Gate Bipolar Transistors (FS-IGBTs) are widely used in various power applications due to their low conduction and switching losses. However, further reductions in cell pitch lead to increased cell density, resulting in higher saturation current that adversely impacts the short-circuit ruggedness essential for applications such as welding machines and motor drives. This paper details the design and fabrication of a 650V, 75A FS-IGBT. By incorporating dummy gate and emitter trench structures within the active gate and optimizing the layout of the three cell structures, the short-circuit characteristics of the device are markedly improved. Experimental tests confirm that the device exhibits both low saturation on-state voltage and short-circuit ruggedness. This study further investigates the circuit parameters related to short-circuit conditions and comprehensively analyzes the impact of each parameter on the short-circuit characteristics of the FS-IGBT. The experimental results indicate that the bus voltage VDC, gate voltage VG, and temperature TC significantly influence the short-circuit performance of the FS-IGBT. Therefore, a moderate decrease in VDC, VG, and TC can effectively enhance the short-circuit ruggedness and the short-circuit withstand time tSC of the device.