Thin Solid Films, Vol.518, No.22, 6348-6351, 2010
Effect of thermal annealing on Ni/Au contact to a-InGaZnO films deposited by dc sputtering
We deposited Ni (15 nm)/Au (30 nm) layers on a-InGaZnO in order to produce low-resistance ohmic contacts by using a dc sputtering method. The samples were annealed at various temperatures for 5 min in Ar ambient. The electrical and the structural properties of the Ni/Au contact to a-InGaZnO were investigated. According to the current-voltage measurements, both the as-deposited and low-temperature annealed samples showed an ohmic behavior. The specific contact resistance of the as-deposited sample was 41 x 10(-5) Omega cm(2), which was the lowest value. Further increasing the temperature above 400 degrees C led to an increase in the specific contact resistance. This is due to the chemical intermixing and formation of the oxide in the contact interface caused by the post-growth thermal annealing. (c) 2010 Elsevier B.V. All rights reserved.