Linearity and robustness evaluation of 150-nm AlN/GaN HEMTs

Mehdi Rzin , Matteo Meneghini (1) , Fabiana Rampazzo , V. Gao Zhan , Carlo de Santi , Riad Kabouche , Malek Zegaoui (2) , F Medjdoub (2, 3) , Gaudenzio Meneghesso (1) , Enrico Zanoni (1)

1 DEI - Dipartimento di Ingegneria de l'Informazione [Padova]
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 WIND - IEMN - WIde baNd gap materials and Devices - IEMN

We report on linearity and robustness of AlN/GaN HEMTs with ultra-thin 4 nm AlN barrier for millimeter wave range applications. Static and dynamic I-V characteristics feature high peak transconductance (g mpeak) of 385 mS/mm, and the transconductance exhibits small changes with gate bias. Semi on-state step stress and 24 h stress tests have been carried out on representative AlN/GaN HEMTs on SiC substrate. No catastrophic failure was identified after semi on-state step stress at V GS = −1.5 V up to V DS = 100 V, whereas a g mpeak drop of 26% was observed in these conditions. Moreover, 24 h stress carried out at different bias voltage along a load line show good robustness of these devices up to V DS = 25 V. In addition, an abrupt gate leakage current increase was identified to be field dependent, and associated with hot spots identified by electroluminescence measurements. Even in presence of a simple SiN passivation without air bridges or field plates, these devices exhibit high power added efficiency up to 40 GHz, thus demonstrating the great potential of AlN/GaN heterostructures.

Domaines: Micro et nanotechnologies/Microélectronique

Mehdi Rzin, Matteo Meneghini, Fabiana Rampazzo, V. Gao Zhan, Carlo de Santi, et al.. Linearity and robustness evaluation of 150-nm AlN/GaN HEMTs. Microelectronics Reliability, 2019, 100-101, pp.113388. ⟨10.1016/j.microrel.2019.06.080⟩. ⟨hal-02356749⟩