Anisotropic conductivity enhancement in inclined W-Cu columnar films
Résumé
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 ρ changes from 1.66 × 10−5 Ωm to 4.28 × 10−5 Ωm 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.