Macroporous silicon: Homogeneity investigations and fabrication tolerances of a simple cubic three-dimensional photonic crystal

Abstract

Large area three-dimensional (3D) photonic crystals have been fabricated either by layer-by-layer methods, colloidal self-assembly, or by macroporous silicon etching. The last mentioned method has proven to be a versatile and fast technique to manufacture simple cubic 3D photonic crystals, having a complete photonic band gap with a width of 4.99% in the infrared spectral range. This report is focused on the investigation of their homogeneity and additional numerical simulations concerning the tolerable disorder allowing still for a complete photonic band gap. Fabry-Pérot resonators, which are realized by 3D photonic crystals containing planar defects, are characterized optically in spatially resolved transmission measurements by scanning infrared Fourier spectroscopy. The impact of the observed inhomogeneities on the complete photonic band gap is studied in detail by modeling the influence of structural parameters. Fabrication tolerances for the simple cubic arrangement of intersecting air spheres in silicon are deduced.