Title :
Cu/Al/Mo/Au and Ni/Al/Mo/Au ohmic contacts for AlGaN/GaN heterostructures
Author :
Sasakura, A. ; Asubar, J.T. ; Tokuda, H. ; Kuzuhara, M.
Author_Institution :
Grad. Sch. of Eng., Univ. of Fukui, Fukui, Japan
Abstract :
In this paper, the effect of thermal expansion in ohmic metals during ohmic annealing was studied to understand the mechanism of n-type ohmic formation in AlGaN/GaN heterostructures. We measured ohmic contact resistance as a function of annealing temperature for metal stacks composed of Cu/Al/Mo/Au, Ni/Al/Mo/Au, and Ti/Al/Mo/Au. Specific contact resistivity values of lower than 10-5 Ωcm2 were, for the first time, achieved for both Cu/Al/Mo/Au and Ni/Al/Mo/Au. The minimum contact resistance for Cu/Al/Mo/Au, Ni/Al/Mo/Au, and Ti/Al/Mo/Au were 0.36 Ωmm, 0.39 Ωmm, and 0.26 Ωmm, respectively.
Keywords :
III-V semiconductors; aluminium; aluminium compounds; contact resistance; copper; electrical resistivity; gallium compounds; gold; molybdenum; nickel; ohmic contacts; rapid thermal annealing; semiconductor heterojunctions; semiconductor-metal boundaries; thermal expansion; titanium; wide band gap semiconductors; AlGaN-GaN heterostructures; AlGaN-GaN-Cu-Al-Mo-Au; AlGaN-GaN-Ti-Al-Mo-Au; Cu-Al-Mo-Au ohmic contacts; Ni-Al-Mo-Au ohmic contacts; Ni-Al-Mo-Au-AlGaN-GaN; n-type ohmic formation; ohmic annealing; ohmic contact resistance; ohmic metals; specific contact resistivity; thermal expansion effect; Aluminum gallium nitride; Annealing; Gallium nitride; Gold; Nickel; Wide band gap semiconductors; AlGaN/GaN heterostructures; contact resistance; ohmic contact; rapid thermal annealing;
Conference_Titel :
Future of Electron Devices, Kansai (IMFEDK), 2015 IEEE International Meeting for
Conference_Location :
Kyoto
Print_ISBN :
978-1-4799-8614-9
DOI :
10.1109/IMFEDK.2015.7158540
