Nanostructuring HfO_2 Thin Films as Antireflection Coatings

摘要

Hafnium dioxide (HfO_2) films deposited on silicon substrates can be nanostructured by the glancing angle deposition technique into various porous morphologies, leading to a variation of the refractive index in a range of 1.94-1.16. This makes HfO_2 thin films effective antireflection coatings on many substrates. For example, a 160-nm-thick HfO_2 film of an appropriate refractive index can cut more than half the reflection of visible light off the surface of SiC or Al_2O_3 substrates. This study provides an easy way to design, prepare, and optimize the performance of antireflection coatings on different substrates.