Crystallization behavior of ion beam sputtered HfO2 thin films and its effect on the laser-induced damage threshold

In this work, we present our results about the thermal crystallization of ion beam sputtered hafnia on 0001 SiO2 substrates and its effect on the laser-induced damage threshold (LIDT). The crystallization process was studied using in-situ X-ray diffractometry. We determined an activation energy for crystallization of 2.6 +/- 0.5 eV. It was found that the growth of the crystallites follows a two-dimensional growth mode. This, in combination with the high activation energy, leads to an apparent layer thickness-dependent crystallization temperature. LIDT measurements @355 nm on thermally treated 3 quarter-wave thick hafnia layers show a decrement of the 0% LIDT for 1 h @773 K treatment. Thermal treatment for 5 h leads to a significant increment of the LIDT values.

Automated summary

The study shows that thermal treatment of hafnia has an impact on the laser-induced damage threshold (LIDT), with a 1-hour treatment at 773K reducing the 0% LIDT, while a 5-hour treatment significantly increases the LIDT values.