Selective sublimation of GaN and regrowth of AlGaN to co-integrate enhancement mode and depletion mode high electron mobility transistors

Thi Huong Ngo (1) , Rémi Comyn (1) , Sébastien Chenot (1) , Julien Brault (2, 1) , Maud Nemoz (1) , Philippe Vennéguès (1) , Benjamin Damilano (1) , S. Vézian (1) , Eric Frayssinet (1) , Flavien Cozette (3, 4) , N. Defrance (5, 6) , François Lecourt (7) , Nathalie Labat (8) , Hassan Maher (4) , Yvon Cordier (1)

1 CRHEA - Centre de recherche sur l'hétéroepitaxie et ses applications
2 UniCA - Université Côte d'Azur
3 3IT - Institut Interdisciplinaire d'Innovation Technologique [Sherbrooke]
4 LN2 - Laboratoire Nanotechnologies et Nanosystèmes [Sherbrooke]
5 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
6 PUISSANCE - IEMN - Puissance - IEMN
7 OMMIC
8 IMS - Laboratoire de l'intégration, du matériau au système

In the present study, the selective sublimation of the p-GaN cap layer of Al(Ga)N/GaN HEMTs is developed to replace the commonly used dry etching with no risk of damage in the barrier layer in order to fabricate enhanced mode transistors. Thanks to this approach, enhancement-mode transistors are fabricated with a threshold voltage between 0 V and +1.5 V depending on the barrier layer aluminum molar fraction and thickness. Furthermore, we show the benefit of the combination of selective sublimation with the regrowth of AlGaN to reduce access resistance in these transistors which can be co-integrated with depletion-mode devices fabricated in the same process in areas where p-GaN has been totally evaporated.

Mots clés: Selective sublimation; Local area epitaxy; Group III-nitrides; High electron mobility transistors

Domaines: Sciences de l'ingénieur [physics]

Thi Huong Ngo, Rémi Comyn, Sébastien Chenot, Julien Brault, Maud Nemoz, et al.. Selective sublimation of GaN and regrowth of AlGaN to co-integrate enhancement mode and depletion mode high electron mobility transistors. Journal of Crystal Growth, 2022, 593, pp.126779. ⟨10.1016/j.jcrysgro.2022.126779⟩. ⟨hal-03741626⟩