Metal-to-Dielectric transition induced by annealing of oriented titanium thin films

Aurélien Besnard (1) , Nicolas Martin (2) , Nicolas Stahl (2) , Luc Carpentier (2) , Jean-Yves Rauch (2)

1 LABOMAP - Laboratoire Bourguignon des Matériaux et Procédés
2 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)

Titanium thin films were deposited by DC magnetron sputtering. The glancing angle deposition (GLAD) method was implemented to prepare two series of titanium films: perpendicular and oriented columnar structures. The first series was obtained with a conventional incident angle α of the sputtered particles (α = 0°), whereas the second one used a grazing incident angle α = 85°. Afterwards, the films were annealed in air using six cycles of temperature ranging from 293 K to 773 K. DC electrical conductivity was measured during the annealing treatment. Films deposited by conventional sputtering (α = 0°) kept a typical metallic-like behavior versus temperature (σ300 K = 2.0 × 10^6 S m-1 and TCR293 K = 1.52 × 10^-3 K-1), whereas those sputtered with α = 85° showed a gradual transition from metal to dielectric. Such a transition was mainly attributed to the high porous structure, which favors the oxidation of titanium films to tend to the TiO2 compound.

Mots clés: sputtering; thin films; electrical properties; metal; dielectric

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Energie électrique; Matériaux; Micro et nanotechnologies/Microélectronique

Aurélien Besnard, Nicolas Martin, Nicolas Stahl, Luc Carpentier, Jean-Yves Rauch. Metal-to-Dielectric transition induced by annealing of oriented titanium thin films. Functional Materials Letter, 2013, 6 (1), pp.5. ⟨hal-00903693⟩