Dry etching of HfO2 and SiO2 optical thin films

HfO2 and SiO2 optical thin films were etched using ion beam etching (IBE), reactive ion etching (RIE) and inductively coupled plasma etching (ICPE) techniques. The influence of reactive gas and ion bombardment energy on the etching rates and surface morphologies of these two coatings was comparatively studied. Low ion bombardment energy with Ar/CHF3 (40/20sccm) realized a preferentially etching of SiO2 with a high rate of 50nm/min, and it almost had no influence of HfO2 coatings.