A silicon nitride coupled germanium detector structure and a preparation method thereof

The invention discloses a silicon nitride coupled germanium detector structure, which is of a lateral photodiode structure, and comprises a silicon substrate; a silicon oxide layer is deposited on theupper surface of the silicon substrate; the silicon oxide layer comprises: a first doped region and a second doped region are formed on both sides of the top silicon layer; A germanium layer is formed on the upper surface between the first doped region and the second doped region, the first electrode and the second electrode are respectively formed on the upper surface of the first doped region and the second doped region, and the first electrode and the second electrode respectively extend upward out of the silicon oxide layer; The silicon nitride waveguide is formed above the germanium layer and has a tapered structure. The silicon nitride waveguide has a first end and a second end, and the first end is smaller than the second end. The invention has the advantages that the integration of the silicon nitride dem