Nanomechanical properties of sputter-deposited HfO₂ and HfₓSi₁ˍₓO₂ thin films

Abstract

The mechanical properties of sputter-deposited HfO₂ and HfₓSi₁ˍₓO₂films were studied as a function of composition using nanoindentation. The elastic modulus and hardness were measured at room temperature for as-deposited films of varying Hf content and for films subjected to annealing at 1000 °C. The elastic modulus and hardness of as-deposited films were found to increase monotonically with increasing HfO₂ content, with the hardness increasing from 5.0 ± 0.3 GPa for pure SiO₂ to 8.4 ± 0.4 GPa for pure HfO₂. All films were found to be harder after annealing at 1000 °C, with the increase for SiO₂films attributed to densification of the SiO₂ network and that for the HfₓSi₁ˍₓO₂films to a combination of phase separation, densification, and crystallization. Show more