We report on fabrication of high quality opaline photonic crystals from large silica spheres, self-assembled in hydrophilic trenches of silicon wafers by using a drawing apparatus with a combination of stirring. The achievements here reported comprise a spatial selectivity of opal crystallization without special treatment of the wafer surface, a filling of the trenches up to the top, leading to a spatially uniform film thickness, particularly an absence of cracks within the size of the trenches, and finally a good three-dimensional order of the opal lattice even in trenches with a complex confined geometry, verified using optical measurements. The opal lattice was found to match the pattern precisely in width as well as depth, providing an important step towards applications of opals in integrated optics. The influence of substrate structure on crystallization is also discussed.
|Title of host publication||Photonic Crystal Materials and Devices III|
|Publisher||International Society for Optics and Photonics SPIE|
|Number of pages||9|
|Publication status||Published - 2006|
|MoE publication type||A4 Article in a conference publication|
|Series||Proceedings of SPIE|
Ye, J., Zentel, R., Arpiainen, S., Ahopelto, J., Jonsson, F., Romanov, S. G., & Sotomayor Torres, C. M. (2006). Crystallization of silica opals onto patterned silicon wafer. In Photonic Crystal Materials and Devices III [61821U] International Society for Optics and Photonics SPIE. Proceedings of SPIE, Vol.. 6182 https://doi.org/10.1117/12.661660