Fabrication of SiO2 microdisk arrays for optics and light trapping experiments

We present a simple silicon based microfabrication process that produces an array of SiO2 microdisks using UV lithography. High-resolution SEM images of these structures indicate a smooth outer microdisk cavity surface. Photoemission measurements were performed at different spots on the microdisk and compared with measurements inside the cavity. A silicon to oxygen atomic concentration ratio of 1:2 obtained during depth profiling confirms that the entire microdisk is made up of stoichiometric SiO2. In contrast, the inner cavity is mostly silicon with native oxide on top. We discuss the usefulness of SiO2 microdisks in optics for light trapping experiments.