Optical properties of porous silicon.: Part II:: Fabrication and investigation of multilayer structures

By knowing the wavelength dependent optical parameters (refractive index n and absorption coefficient alpha) and the obtained thickness of porous silicon (PS) layers when anodizing boron-doped Si wafers, one can design and realize periodic structures by alternating the current density during anodization. Such periodicity in the structure-and thus in optical properties within a film-results in a superlattice, which acts as a Bragg grating. By considering the proper Bragg conditions, the fabrication of optical filter/reflector components can be performed in a simple manner. In this paper, both theoretical and experimental aspects of the fabrication procedure are investigated. (C) 2003 Elsevier B.V. All rights reserved.