Magnetic, Electrical and Surface Morphological Characterization of AuGe/Ni/Au Ohmic Contact Metallization on GaAs/AlGaAs Multilayer Structures

Authors T.S. Abhilash, Ch. Ravi Kumar, G. Rajaram
Affiliations School of Physics and Centre for Nanotechnology, University of Hyderabad, Hyderabad - 500046, India
Issue Volume 3, Year 2011, Number 1, Part 2
Dates Received 04 February 2011, in final form 28 April 2011, published online 08 May
Citation T.S. Abhilash, Ch. Ravi Kumar, G. Rajaram, J. Nano- Electron. Phys. 3 No1, 396 (2011)
PACS Number(s) 73.61.Ey, 75.70. – i, 85.40.Ls
Keywords GaAs/AlGaAs, Hall sensors, Magnetic properties (7) , Ohmic contact (5) .
A process issue arising from the use of ferromagnetic Nickel in the AuGe/Ni/Au Ohmic contact metallization is studied in the context of magnetic field sensors and HEMT devices made using GaAs/AlGaAs multilayer structures with the two dimensional electron gas layer. The dependence of magnetization, contact resistance, adhesion, surface roughness and current distribution of alloyed Ohmic contacts on parameters such as Ni layer thickness, anneal temperature and Au-Ge alloy composition are discussed. The magnetization measurements provided some new and interesting insights into changes occurring in the metallization layers prior to alloying.

List of References