Poly-Si thin layers for high speed photodetectors

Thin layers of polycrystalline silicon as optically absorbing material for photodetecting applications represents a promising way for achieving fast devices which can be integrated in optoelectronic circuits for optical communication. One of this type of device is the MSM photodiode. In this paper, the preparation and characterization of polysilicon thin layers together with technological processes for an MSM type photodetector are presented. The crystalline structure, surface morphology and optical properties were investigated by AFM techniques, X-ray diffraction and spectrophotometer measurements. The dynamic response of the device was calculated with the designed parameters.