New plasma shaping technology for optimal high voltage diode performance

Abstract

In this paper, a newly developed diode technology platform for 3.3 kV, 4.5 kV and 6.5 kV diodes for next generation high power IGBT modules will be presented. The new diode range offers low losses and soft recovery characteristics combined with a high reverse recovery safe operating area and superior surge current capability. The new diode technology employs a double local lifetime-control method using He ++ irradiation to control the on-state electron-hole distribution on both the anode and cathode sides of the diode.

Future trends in high‐power bipolar metal‐oxide semi‐conductor controlled power semi‐conductors

“…The second method is based on the emitter controlled ‘EmCon’ concept with a low doped and shallow profile anode having no local lifetime [38]. It is important to mention that uniform lifetime control with electron irradiation or cathode side local lifetime control are needed for overall excess carrier reduction and reverse recovery tail control [39]. For high‐voltage diodes, both concepts have advantages and drawbacks.…”

Influence of carrier lifetime distribution on the current filament in high voltage diode

“…In order to improve the fast and soft recovery characteristic of high voltage diode, some technologies by improved structures and carrier lifetime controls were implemented. In recent years, the carrier lifetime control technologies mainly include the high energy electron irradiation resulting in a uniform lifetime distribution [6][7][8], and the proton or He 2+ irradiation providing a local low lifetime distribution [8][9][10][11]. The carrier lifetime distribution determines the on-state plasma distribution in the n − base, which can influence the extraction velocity of the plasma and the power loss during reverse recovery, and what's more, it even influences the formation and movement of current filaments under dynamic avalanche [12][13][14].…”

An analysis of the dynamic avalanche mechanism of an improved FCE diode with a deep p+ adjusting region

“…As a result, the high voltage diode produces a failure due to a dynamic avalanche. In order to obtain a fast and soft recovery, some methods and measures, such as new anode or cathode structures OE1 4 and carrier lifetime control techniques OE5;6 , are used to decrease the carrier injection efficiency to improve the soft recovery characteristic of the freewheeling diode. The field charge extraction (FCE) cathode is a new structure for the high voltage fast and soft recovery diode (FSRD) OE1 , in which part of the n C cathode region is replaced by a shallow p C adjusting region to adjust the carrier concentration during reverse recovery and obtain a trade-off between the recovery loss and softness.…”