Ion-assisted deposition of moisture stable HfO2 thin-films

HfO2 (hafnium oxide) is a common material used for manufacture of UV filters due to being transparent down to about 250 nm. Also, it exhibits less sensitivity to moisture instability than many other thin-film materials. It is possible to make fully dense, moisture stable films using IAD (ion-assisted deposition). However, unlike many other oxides, it is necessary to use a mixture of argon and oxygen.

This paper reports the process parameters used to make moisture stable HfO2, the optical properties of HfO2 in the UV-visible spectral region and gives an example of a moisture stable thin-film coating of a HfO2/SiO2 LWP filter.