Impact of Vth shift on Ron in E/D mode GaN on Si power transistors: Role of dynamic stress and gate overdrive
In this work, we revealed the impacts of V<sub>TH</sub> shift on R<sub>ON</sub> in enhancement /depletion mode (E/D mode) GaN transistors under dynamic AC (1 k 1 MHz) stress. With newly developed fast dynamic characterization techniques, we achieved data acquisition within 120 ns after each stress pulse throughout the entire stress time ranging from 10<sup> 7</sup> s up to 10<sup>3</sup> s. V<sub>TH</sub> shift and the consequent R<sub>ON</sub> increase under dynamic stress, which are more relevant to high frequency switching operation, exhibits frequency dependence and is smaller than that under conventionally used static stress. Furthermore, distinctive R<sub>ON's</sub> susceptibilities to V<sub>TH</sub> shift between E mode and D mode GaN transistors are revealed and analyzed. The correlation between V<sub>TH</sub> shift and R<sub>ON</sub> facilitates the assessment on how much V<sub>TH</sub> shift a GaN power switch can tolerate.
2016 28th International Symposium on Power Semiconductor Devices and ICs (ISPSD)