Strain-Reduction Induced Rise in Channel Temperature at Ohmic Contacts of GaN HEMTs

Steven Duffy (1) , Brahim Benbakhti (1) , Karol Kalna (2) , Mohammed Boucherta (3) , Wei Zhang (4) , Nour Eddine Bourzgui (3, 5) , Ali Soltani (3, 6, 7, 5)

1 LJMU - Liverpool John Moores University
2 Swansea University
3 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
4 CASIC - China Aerospace Science and Industry Corporation
5 PUISSANCE - IEMN - Puissance - IEMN
6 LN2 - Laboratoire Nanotechnologies Nanosystèmes
7 3IT - Institut Interdisciplinaire d'Innovation Technologique [Sherbrooke]

ABSTRACT Operating temperature distributions in AlGaN/GaN gateless and gated devices are characterized and analyzed using the InfraScope temperature mapping system. For the first time, a substantial rise of channel temperature at the inner ends of ohmic contacts has been observed. Synchrotron radiationbased high-resolution X-ray diffraction technique combined with drift–diffusion simulations show that strain reduction at the vicinity of ohmic contacts increases electric field at these locations, resulting in the rise of lattice temperature. The thermal coupling of a high conductive tensile region at the contacts to a low conductive channel region is an origin of the temperature rise observed in both short- and long-channel gateless devices.

Mots clés: AlGaN/GaN based devices; ohmic contact; self-heating; infrared camera; high-resolution X-ray diffraction

Domaines: Sciences de l'ingénieur [physics]

Steven Duffy, Brahim Benbakhti, Karol Kalna, Mohammed Boucherta, Wei Zhang, et al.. Strain-Reduction Induced Rise in Channel Temperature at Ohmic Contacts of GaN HEMTs. IEEE Access, 2018, 6, pp.42721-42728. ⟨10.1109/ACCESS.2018.2861323⟩. ⟨hal-02273401⟩