Anisotropic conductivity enhancement in inclined W-Cu columnar films

Two immiscible metals (W and Cu) were deposited using two metallic targets by GLAD co-sputtering. A wet chemical etching technique was implemented to remove the copper and modify the typical inclined microstructure into a more porous architecture. The electrical resistivity behavior of the co-sputtered W-Cu film was characterized as a function of temperature before and after wet chemical etching. The results show that the columnar microstructure exhibits metallic-like electrical properties. The average DC electrical resistivity rho changes from 1.66 x 10 (5) Omega m to 4.28 x 10 (5) Omega m after etching. The anisotropy at room temperature is A = 1.8 +/- 0.1 for as-deposited W-Cu film and reaches 2.8 +/- 0.1 after the etching procedure. (C) 2018 Elsevier B.V. All rights reserved.