Title :
Ti/Al/Ni/Au and Ti/Al/Pt/Au multi-layer ohmic contacts on AlxGa1-xN/GaN heterostructures
Author :
Zhou, H.M. ; Shen, B. ; Chen, D.J. ; Tang, N. ; Chen, T.S. ; Jiao, G. ; Ru, L. ; Zhang, R. ; Shi, Y. ; Zheng, Y.D.
Author_Institution :
Jiangsu Provincial Key Lab. of Photonic & Electron. Mater. Sci. & Technol., Nanjing Univ., China
Abstract :
The ohmic contacts of Ti/Al/Ni/Au and Ti/Al/Pt/Au multi-layer on unintentionally-doped Al0.22Ga0.78N/GaN heterostructures have been investigated. The specific contact resistivities of 1.26×10-6 Ω·cm2 for Ti/Al/Ni/Au contact and 1.97 × 10-5 Ω·cm2 for Ti/Al/Pt/Au contact were obtained. It is found that the Pt element in Ti/Al/Pt/Au multi-layer influent the diffusion of Al atom into the Au layer, which results in the higher contact resistivity of Ti/Al/Pt/Au contact than that of Ti/Al/Ni/Au one. The formation of excellent ohmic contact on the Al0.22Ga0.78N/GaN heterostructures is attributed to the existing of a compatible barrier between the metal electrode and the carrier channel at the Al0.22Ga0.78N/GaN hetero-interface. The width of the barrier depends on the annealing temperature and duration.
Keywords :
aluminium; aluminium compounds; annealing; contact resistance; gallium compounds; gold; nickel; ohmic contacts; platinum; semiconductor heterojunctions; titanium; AlxGa1-xN-GaN; Ti-Al-Ni-Au; Ti-Al-Pt-Au; Ti/Al/Ni/Au; Ti/Al/Pt/Au multi-layer Ohmic contacts; carrier channel; diffusion; higher contact resistivity; metal electrode; specific contact resistivities; unintentionally-doped Al0.22Ga0.78N/GaN heterostructures; Annealing; Artificial intelligence; Conductivity; Contact resistance; Gallium nitride; Gold; Ohmic contacts; Temperature; X-ray diffraction; X-ray scattering;
Conference_Titel :
Junction Technology, 2004. IWJT '04. The Fourth International Workshop on
Print_ISBN :
0-7803-8191-2
DOI :
10.1109/IWJT.2004.1306788
