Annealing influence on optical performance of HfO2 thin films

Abstract

Hafnium oxides (HfO2) retain mechanical resilience, thermal stability, and chemical resistivity due to which it is used diversely in various high-tech applications in optics and integrated circuit technology. In the present article, we study the influence of thermal annealing on the optical performance of HfO2 antireflective thin films (H@ATF). Firstly, H@ATF were designed and fabricated according to simulation parameters via electron beam evaporation. The H@ATF were annealed in the temperature range of 100 °C–900 °C for an hour with a ramp speed of 5 °C rise in temperature. It is experimentally evaluated that annealing influence the optical properties of thin films, with increasing temperature there is a shift of anti-reflectance (AR) efficiency (wave minima) towards lower wavelength as the phase transition occurs from amorphous to crystalline state. The transformations from amorphous to crystalline phase influence the optical properties, refractive index, and wetting performance of H@ATF. Herein, we presented a cost-effective system to make hydrophilic H@ATF and study the annealing influence on its optical performance.