Microstructural characterisation of TiAlTiAu and TiAlPdAu ohmic contacts to AlGaN/GaN

Fay, Mike W.; Harrison, Ian; Birbeck, J.C.; Hughes, B.T.; Uren, M.J.; Martin, T.; Brown, Paul D.

Abstract

Ti/Al/Ti/Au and Ti/Al/Pd/Au contacts to AlGaN/GaN have been investigated to ascertain the effect of annealing temperature on the structural evolution of the contacts. Ti/Al/Ti/Au contacts become ohmic after rapid thermal annealing at 750°C or higher, corresponding to the formation of an interfacial TiN phase, with inclusions penetrating through the AlGaN layer observed after annealing at 950°C. The Pd layer is shown to be more efficient at inhibiting diffusion of Au to the interface than Ti. Ohmic behaviour was not seen with the Ti/Al/Pd/Au scheme. Either the presence of Au at the interface may improve ohmic behaviour, or the Ti:Al ratio is insufficient in this scheme.

Citation

Fay, M. W., Harrison, I., Birbeck, J., Hughes, B., Uren, M., Martin, T., & Brown, P. D. Microstructural characterisation of TiAlTiAu and TiAlPdAu ohmic contacts to AlGaN/GaN. In M. Aindow, & C. Kiely (Eds.), Electron microscopy and analysis 2001: proceedings of the Institute of Physics Electron Microscopy and Analysis Group Conference, University of Dundee, 5-7 September. IOP Publishing Ltd

• Deposit Date: May 19, 2011
• Peer Reviewed: Peer Reviewed
• Issue: 168
• Series Title: Institute of Physics conference series
• Book Title: Electron microscopy and analysis 2001: proceedings of the Institute of Physics Electron Microscopy and Analysis Group Conference, University of Dundee, 5-7 September
• ISBN: 9780750308120
• Keywords: TEM, TiAlTiAu, TiAlPdAu, AlGaN/GaN, ohmic contact
• Public URL: https://nottingham-repository.worktribe.com/output/1023317
• Related Public URLs: http://iopscience.iop.org/