Experimental study of 650V AlGaN/GaN HEMT short-circuit safe operating area (SCSOA)

Experimental study of the short-circuit performance for a 600V normally-off p-gate GaN HEMT

“…The injection of holes into the gate increases with the amount of the current I G . Therefore, an assumption of hole accumulation under the gate [2] can be made.…”

“…During an SC the device has to be capable of a high power dissipation, that eventually leads to an excessive self-heating related failure. A previous publication of normally-on GaN HEMT SC robustness [2] concluded the failure to be an electrical effect rather than an impact of a thermal issue. It is predicted, that the electrical impact occurs due to an accumulation of holes under the gate, which generates localised high electric fields and causes premature breakdown.…”

Electrical and thermal failure modes of 600 V p-gate GaN HEMTs

“…The influence of a V GS has already been investigated [1], therefore the voltage for all the conditions is defined as nominal V GS = 3.5 V. The on-state performance of the DUT predicts an insignificant reduction, regarding the range of nominal bias currents I G . In order to investigate the transferability on the SC capability, the condition A features a high value within the range, while the condition B features a low.…”

“…A recent study on the short-circuit safe operating area (SCSOA) of a depletion-mode HEMT [1] refers the short-circuit failure to an avalanche generation of accumulated holes under the gate at high electrical fields. Additionally, a reduction of the withstand capability has been observed, according to an increasing drain-source voltage and gate-bias condition.…”

On the trap assisted stress induced safe operating area limits of AlGaN/GaN HEMTs

“…Long term reliability of these devices has been studied in greater details in the recent literature [1]- [7]. However, a clear understanding of the physical phenomena active under high electric field and high current injection conditions, which define the safe operating area (SOA) limit in GaN HEMT, is still missing in the literature [8], [9]. Therefore, a study to gain insight into possible degradation mechanisms which limit the SOA reliability in GaN HEMT is a worthwhile effort.…”