Influence of two post-treatment methods on properties of HfO2 thin films

HfO2 thin films were prepared by electron beam evaporation technique and photoelectric maximum control method. Two kinds of post-treatment methods, both oxygen plasma bombardment and anneal in air, were employed to treated with the samples. Optical transmittance, absorption and laser induced damage threshold (LIDT) at 1064 nm were measured before and after the treatments. It is shown that post-treated with oxygen plasma is better than annealing in air to decrease the absorption and improve the LIDT of HfO2 thin films. The absorption of HfO2 thin film dropped from 34.8 ppm to 9 ppm and the LIDT at 1064 nm increased from 10.0 J/cm2 to 21.4 J/cm2, after post-treated with oxygen plasma. The difference between the two post-treated methods is studied in this article.