Physical Characterization of Hafnium Oxide Thin Films Annealed in Vacuum

Abstract:

Hafnium oxide (HfO₂) is a material characterized by a good mechanical, thermal and chemical stability and is used as a material in a variety of technological applications in optics and electronics. In this work the influence of annealing temperature on the mechanical structural properties of amorphous HfO₂ thin film was explored. Films were deposited by electron beam evaporation and annealed in the temperature range from 200 °C to 500 °C in vacuum. Mechanical properties such as hardness and elastic modulus were determined using nanoindentation, while cohesive-adhesive properties of the film using a scratch test. Surface morphology was determined using a confocal microscope and structure using XRD. The transformation of amorphous phase of the films to the nanocrystalline monoclinic phase was observed after vacuum annealing at 500 °C. This crystallization leads to increase in hardness on one hand but also to growth of brittleness and in turn to decrease in scratch resistance on the other hand.

• Periodical: Key Engineering Materials (Volume 784)
• Pages: 135-140
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.784.135
• Online since: October 2018
• Authors: Lukáš Václavek*, Jan Tomaštík, Libor Nožka, Radim Čtvrtlík
• Keywords: Annealing, Hafnium Oxide, Nanoindentation, Scratch Test

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