1. Ohmic contact formation of Ti/Al/Ni/Au to n-GaN by two-step annealing method
- Author
-
Chen, Z.Z., Qin, Z.X., Hu, C.Y., Hu, X.D., Yu, T.J., Tong, Y.Z., Ding, X.M., and Zhang, G.Y.
- Subjects
- *
ELECTRIC lines , *ENERGY industries , *SEMICONDUCTORS , *ANNEALING of crystals - Abstract
The thermal annealing effects on Ti/Al/Ni/Au Ohmic contact to n-GaN are investigated by current–voltage (I–V) characteristics and transmission line method (TLM) measurements. The cladding layer of Ni/Au on Ti/Al plays two roles: preventing inter-diffusion of Ti, Al, Au and anti-oxidation of the contacting layer. The specific contact resistance (ρc) of Ti/Al/Ni/Au to n-GaN increases slightly at first with the increasing annealing temperature (Ta). When Ta increases above 500 °C, ρc decreases monotonously in the range of 400–900 °C. However, the morphology of the contact degrades gradually when Ta increases above 600 °C. The minimum of ρc is obtained as
9.65×10-7 Ω cm2 by two-step annealing method in this work. Finally, the roles of two-step annealing method in the formation mechanism of the Ohmic contact to n-GaN are also discussed. [Copyright &y& Elsevier]- Published
- 2004
- Full Text
- View/download PDF