F. Pfirsch

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We present a theoretical analysis of the formation of current filaments leading to the latch-up state that can occur during the turn-off process in a cell array of high-voltage (3.3 kV) trench insulated-gate bipolar transistors (trench IGBTs). Our investigations, based on self-consistent physical device simulations, aim at understanding the behavior of(More)
This paper discusses the trade-off between surge-current capability on the one hand and reverse-recovery charge, ruggedness and softness of high-voltage diodes on the other hand. Diodes with a CIBH (Controlled Injection of Backside Holes) structure in front of the cathode and a highly doped p +-region combine high surge-current capability with(More)
Current filaments are inherently three-dimensional phenomena regardless of the chip topography, which can be stripe-or checkerboard-shaped. Therefore, we consider an alter-native mapping of the real-chip IGBT cell topography to a quasi-3D simulation geometry in order to attain a computationally affordable approximation of 3D-filamentation effects that limit(More)
TCAD simulations of power devices are an important tool to investigate destruction mechanisms of power diodes and IGBTs. It is found that the dynamics of filamentation is the key for understanding the limits of the safe operation area. For both diodes and IGBTs, destructive and non-destructive filamentation mechanisms are identified and the resulting(More)
In IGBTs avalanche breakdown usually sets on in the edge termination structure. In consequence of electrical crosstalk, the destruction mechanism in very thin devices is confined to the neighboring cells in the active part of the chip. Thus, in order to achieve the largest possible safe-operating area, design optimization has to focus on the edge(More)
We studied different destruction modes of planar cell 1200V "non-punch-through" and "fieldstop" insulated gate bipolar transistors in forward blocking mode using simulation tools. Branches of negative differential resistance are explained with certain device properties and a dynamic distortion of the electric field. Careful design of the device avoid these(More)
The on-state current voltage characteristic of thyristors is investigated by numerical one-dimensional simulation. For sufficiently high p-base concentration, an abrupt increase in on-state voltage is observed above a critical current density. By driving the device to higher currents, a reduction of on-state voltage occurs. Similar results are obtained for(More)
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