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

Autocloning technique is an attractive deposition method to make photonic crystals since it can produce various photonic crystals by changing the substrate periodicity and the structure of the stacking materials. We report a novel method to fabricate autocloned photonic crystals. This method has better step-coverage, higher deposition rate and large deposition area than the sputtering method. We successfully preserved the periodic surface corrugation after the deposition of multilayer stacks by using an E-beam gun evaporation with ion-assisted deposition (IAD). Freedoms of the shaping process can be controlled by the power of IAD and the time of the ion source etching. The ion source etching is a physical etching process without any chemical reaction and dangerously reactive gas. The process parameters were described in this paper. During the deposition process, the refractive index can be adjusted by changing the deposition rate and the substrate temperature. The deposition rate was about 0.7-1 nm/s for SiO₂ which is almost ten times faster than the sputtering method. So this method is good for the mass production of photonic crystals.