Abstract
Role of linear nucleation centres (surface grooves) in formation of macro‐pores has been studied for n‐type Si. It has been found that linear nucleation centres, contrary to the case of point nucleation pits, initiate formation of semi‐regular pore pattern: along the grooves the pores are arranged randomly as a result of self organization process, across the grooves they follow the prescribed period a. The average distance between the pores along a groove line depends on a, and decreases as a increases. At the optimal value of etching current density and seed period a, the distinct pores can merge, thus forming a periodic structure of one‐dimensional photonic crystal. Optical properties of grooved structures with merged pores have been investigated by means of Fourier infrared reflection micro‐spectroscopy in the spectral range from 1.45 μm to 16.5 μm. Reflectance spectra reveal presence of photonic band gaps which positions in the middle IR range are in a good agreement with calculations by transfer matrix method. The fabrication approach developed is promising for application in silicon‐based photonics. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)