Low noise photosensitive device structures based on porous silicon

摘要

Photosensitive metal/PS/c-Si structures with oxidized and non-oxidized porous silicon (PS) layers were fabricated. The structures were made from moderately doped p-type c-Si substrates with dielectric windows and "stop" rings prepared using standard c-Si photodiode fabrication technology. Using this technology allowed orders of magnitude decrease the reverse currents of metal/PS/c-Si device structures. The best oxidized and non-oxidized structures have a dark reverse current of 20 nA/cm~2 at 10 V bias and a noise current of 0.16 x 10~(-13) A/Hz~(1/2). Two types of photosensitive structures were obtained―photodiode structures with PS as an antireflection coating/optical window and bipolar phototransistor-like structures. Photodiodes are characterized by a quantum efficiency of 75% while "phototransistors" have a gain up to 11.