SPLITTING OF POROUS SILICON MICROCAVITY MODE DUE TO THE INTERACTION WITH SI-H VIBRATIONS

A Fabry-Perot microcavity centred in the infrared around 2000-2200 cm( -1) has been realised by controlling the current and the time of a ste ps anodization procedure of a p(+) type silicon wafer in an electroche mical cell with a hydrofluoric acid solution. The interaction of the c avity mode, detectable as a sharp deep in the high reflectivity platea u, with the Si-H vibration modes gives rise to a splitting of the cavi ty mode dispersion curve (frequency vs wavevector) and to an enhanceme nt of the infrared absorption of the Si-H bands. Both, the dispersion of the coupled modes (cavity/Si-H modes) and their infrared absorption enhancement have been studied. (C) 1998 Elsevier Science S.A. All rig hts reserved.