Cell pitch influence on the current distribution during avalanche operation of trench IGBTs: Design issues to increase UIS ruggedness

Abstract

Actual design of power devices considers ruggedness in harsh operating conditions as mandatory to meet the alwaysincreasing demand for lifetime device reliability, this being particularly true when the devices are used in safety-critical automotive applications. In this paper we show, for the first time, that a careful engineering of the standard cell geometry can shift the avalanche current from termination to active region and eventually lead to increased avalanche ruggedness without impacting the forward capability of a 1200V-rated fieldstop trench IGBT designed for power traction purposes.

Development of an HBM-ESD tester for power semiconductor devices

“…This a complex behavior and it is a typical experimental evidence that highlights the presence of a strong current filamentation in the device [2], [7]. The current filamentation is due to the presence of a negative differential resistance (NDR) in the reverse I-V curve of the DUT and it becomes more relevant when the conduction carriers concentration becomes comparable to the doping concentration of the Drift layer [8]. The more the oscillations are large, the more the current density is higher into the filaments, with the consequent voltage variation.…”

1200 V FS‐IGBT with electric field modulation layer to improve trade‐off between avalanche ruggedness and on‐state voltage drop

“…In 2014, Spirito et al proposes the FS‐IGBT with the positive differential resistance branch in the I C – V CE avalanche curve by decreasing injection efficiency of the collector [9]. Riccio et al point out that the IGBT with large cell pitch has the better avalanche ruggedness [10]. However, all of these methods increase the on‐state voltage drop of the IGBTs.…”