Electrical resistivity of Ti–Zn mixed oxide thin films deposited by atomic layer deposition

Abstract

Ti–Zn mixed oxide thin films, with thickness less than 50nm, were grown with atomic layer deposition (ALD) technique at low temperature (90°C) varying the composition. ALD is a powerful chemical technique to deposit thin films with thickness of few atomic layers. ALD oxide material growth is achieved by dosing sequentially the metal precursor and the oxidizing agent. Thanks to ALD nature of layer by layer growth it was possible to realize mixed metal, Ti and Zn, oxide thin films with controlled composition, simply by changing the number of cycles of each metal oxide layer. Structural and electrical properties of the prepared thin films were studied as a function of their composition. Synchrotron radiation X-ray diffraction technique was used to follow thin film crystallization during sample annealing, performed in situ. It was observed that the onset temperature of crystallization raises with Ti content, and sample structure was Zn2TiO4 phase. Electrical resistivity measurements were performed on crystalline samples, annealed at 600°C, revealing an increase in resistivity with Ti content.