A Parametric Technique for Traps Characterization in AlGaN/GaN HEMTs

A new parametric and cost-effective tech- nique is developed to decouple the mechanisms behind current degradation in AlGaN/GaN HEMTs under a nor- mal device operation: self-heating and charge trapping. A unique approach that investigates charge trapping using both source (IS) and drain (ID) transient currents for the first time. Two types of charge trapping mechanisms are identified: (i) bulk charge trapping occurring on a time scale of less than 1 ms, followed by (ii) surface charge trapping with a time constant larger than a millisecond. Through monitoring the difference between IS and ID, a bulk charge trapping time constant is found to be independent of both drain (VDS ) and gate (VGS ) biases. Surface charge trapping is found to have a much greater impact on a slow degrada- tion when compared to bulk trapping and self-heating. At a short timescale ( 1 ms), the dynamic ON resistance degradation is predominantly limited by surface charge trapping

A Parametric Technique for Traps Characterization in AlGaN/GaN HEMTs

A new parametric and cost-effective technique is developed to decouple the mechanisms behind current degradation in AlGaN=GaN HEMTs under a normal device operation: self-heating and charge trapping. Our unique approach investigates charge trapping using both source (IS) and drain (ID) transient currents for the first time. Two types of charge trapping mechanisms are identified: (i) bulk charge trapping occurring on a time scale of less than 1 ms, followed by (ii) surface charge trapping with a time constant larger than a millisecond. Through monitoring the difference between IS and ID, a bulk charge trapping time constant is found to be independent of both drain (VDS) and gate (VGS) biases. Surface charge trapping is found to have a much greater impact on a slow degradation when compared to bulk trapping and self-heating. At a short timescale ( 1 ms), the dynamic ON resistance degradation is predominantly limited by surface charge trapping