Fabrication of autocloned photonic crystals using electron-beam guns with ion-assisted deposition

The autocloning technique is an attractive deposition method for the making of photonic crystals. With it various photonic crystals can be produced simply by changing the substrate periodicity and the structure of the stacking materials. We report on a method for the fabrication of autocloned photonic crystals. This method has better step-coverage, a higher deposition rate and a larger deposition area than can be achieved by the more traditional sputtering method and the periodic surface corrugation is preserved even after ion-assisted deposition (IAD) of multilayer stacks using E-beam gun evaporation. The shaping process can be freely controlled by controlling the IAD power and the ion source etching time. Ion source etching is a physical etching process which does not require any chemical reaction or dangerous reactive gas. The process parameters are described in this paper. The refractive index can be adjusted by changing the deposition rate and the substrate temperature during the deposition process. The deposition rate is about 0.7-1 nm/s for SiO₂ which is almost ten times faster than that of the sputtering method. This makes this method good for the mass production of photonic crystals.