Improvement of a capacitive UV-sensor by porous silicon powders embedded in epoxy on porous silicon film

A high-sensitivity porous silicon (PS) powder-based capacitive UV-sensor is developed on the PS-film structure. To the best of our knowledge, this is the first report on PS powder-based capacitive UV-sensors. An anodization etching approach based on a sawtooth waveform electrolytic voltage is adopted to get sufficient PS-powders. The collected PS-powders are embedded on the PS-film and covered with epoxy to improve the UV sensitivity. The results show that the increase of UV sensitivity on capacitive characteristics is almost linearly related to the PS powder mass embedded inside. The proposed method is suitable for fine-tuning and improving the equivalent permittivity of the capacitive UV-sensor without changing the device geometry design, which can be compatibly applied to Si-VLSI technology.