Manufacturing method of photonic crystal
A manufacturing method of a photonic crystal is provided. In the method, a high-refractive-index material is conformally deposited on an exposed portion of a periodic template composed of a low-refractive-index material by an atomic layer deposition process so that a difference in refractive indices or dielectric constants between the template and adjacent air becomes greater, which makes it possible to form a three-dimensional photonic crystal having a superior photonic bandgap. Herein, the three-dimensional structure may be prepared by a layer-by-layer method.
1. A method of manufacturing a photonic crystal with a photonic bandgap, the method comprising:
forming a periodic three-dimensional structure comprising a material having a first refractive index and a plurality of gaps; and conformally depositing exposed surfaces of the periodic three-dimensional structure with a material having a second refractive index greater than the first refractive index; and wherein the material having the first refractive index comprises at least one of polyurethane, Si, SiO 2 , and Al 2 O 3 ; wherein the material having second refractive index is TiO 2 and wherein disposition of the TiO 2 upon the periodic three-dimensional structure is performed using an atomic layer deposition (ADL); and wherein disposition comprises supplying a Ti precursor for the material having the second refractive index into a reaction chamber receiving the periodic three-dimensional structure at a temperature ranging from approximately 50° C. to approximately 150° C., to coat the periodic three-dimensional structure with the Ti precursor; supplying inert gas into the reaction chamber to purge the reaction chamber; supplying an oxygen precursor into the reaction chamber to form TiO 2 on the periodic three dimensional structure through chemical reaction of the Ti precursor and the oxygen precursor; and supplying inert gas into the reaction chamber to purge the reaction chamber.
2. The method of claim 1 , wherein the periodic three-dimensional structure is prepared by a method comprising:
forming a master comprising a plurality of photoresist patterns on a first substrate, the photoresist patterns having a predetermined height, width and space;
forming an elastomer on the master;
curing the elastomer, and separating the cured elastomer from the master to form a template;
filling troughs of the template with a polymer material, and curing the polymer material by contacting the template with a second substrate;
removing the template from the second substrate to form a first polymer layer; and
repeating the filling of the troughs of the template with the polymer material, the curing of the polymer material and the removing of the template from the second substrate, to thereby form at least one nth polymer layer on an (n−1)th polymer layer, wherein the nth polymer layer is rotated by 90° with respect to the (n−1)th polymer layer, and shifted in parallel by half the space with respect an (n−2)th polymer layer, where n is a positive integer greater than 1.