Fabrication of photonic crystals in tantalum pentoxide films

In this paper, we show some aspects of the fabrication of photonic crystal (PC) structures in tantalum pentoxide films (Ta2O5). This includes the proximity correction for the e-beam lithography, the resist mask, the metallic etching mask, and the deep etch process into the pentoxide. PC devices, consisting of sub-micron holes with a diameter of down to 300 nm, perpendicular side walls and an aspect ratio of 5, were fabricated. Optical properties of some fabricated PC components and its strong dependence on their geometrical parameters are presented.