Integration of a micro-incandescent lamp and an interferometric filter for optical applications

In this work we propose an integration of two kinds of optical devices: an incandescent micro lamp and an interferometric filter, both fabricated on silicon technology. The micro lamp is based on a chromium micro resistor, working as a lamp filament, embedded between two oxynitride films and self-sustained through the partial silicon substrate etching using KOH solutions. The interferometric filters were fabricated through the deposition of periodically alternated PECVD Si(3)N(4) and SiO(2) films whose thicknesses were previously defined by numerical simulations. We present the fabrication of these two devices separately and its integration in a hybrid way. The results demonstrated that light filtering can be obtained on micro-lamps light emission spectrums when integrated with interferometric filters, at the wavelength intervals defined by filter transmittance spectrums. Electrical characterization allowed determining the necessary current to obtain constant and stable light emission from micro lamps. The possibility of integration in a unique process, in a quasi-monolithic integration, is proposed.