SEGR Study on Power MOSFETs: Multiple Impacts Assumption

Abstract

Expérience GANILInternational audienceThis paper presents experimental data showing heavy ions inducing gate degradation in power MOSFETs. In the experiments, backside and front-side irradiations are performed. During backside irradiation, the heavy ion ranges are tuned in such way to control whether they hit the gate or not. Gate-to-source current Igss ( ) is measured versus heavy ions (H.I.) fluence . Post-irradiation- gate-stress-test (PGST) allows measurement of gate breakdown voltage VBD( ) which is observed to decrease with (H.I.) fluence. Based on these experimental results, a hypothesis of substrate- generated carriers impact overlap of multiple strikes may explain gate degradation until SEGR triggering. This last hypothesis is supported by a statistical model approach of heavy ions multiple impacts

TCAD Simulation of the Single Event Effects in Normally-off GaN Transistors after Heavy Ion Radiation

“…Other studies have shown that the dielectric breakdown was mainly affected by pre existing damage [33] and SEGR could also be triggered by ions crossing only the epitaxy without reaching the oxide [34]. Fig.…”

SEGR characterization of power MOSFETs: A new insight on PIGST associated to a non-destructive charge collection measurement tool

“…In case of SEGR, the minimum fluence cumulated before the event onset is about 10 3 ions.cm -2 . As described in a previous study [19], one can assume that these fluence limits belong to the "multiple impacts" regime. Complete analysis of the results will be provided in the final version of the paper.…”

“…An abundant literature exists on this topic [1] however the mechanism that triggers the gate degradation or rupture is still under investigation and SEGR/SEB current test methods and test requirements [16]- [17] are still challenged. As of today, current issues address range or fluence requirements during ground-testing [19]- [20], relevance of the use of LET at the device surface for failure risk assessment purpose [18], [21], cumulative degradation hypothesis [20] rather than single ion impact effect, PIGST validity or relevance , etc… This is of main concern for the selection of devices dedicated to Space applications.…”

Study of heavy ion induced single event gate rupture effect in SiC MOSFETs

“…2,3) As with Si power MOSFETs, SiC MOSFETs are subject to single event effects in the space environment, most notably single event burnout (SEB) and single event gate rupture (SEGR). [4][5][6] SEB can result in catastrophic device failure, which has been a hot research area in recent years. [7][8][9][10][11] In comparison, SEGR has only recently begun to garner interest in recent years.…”