Horizontal germanium detector structure and preparation method thereof

The present invention discloses a horizontal germanium detector structure. The horizontal germanium detector structure is a horizontal photodiode structure and comprises a silicon substrate; a siliconoxide layer is deposited at the upper surface of the silicon substrate; the silicon oxide layer comprises top silicon, a first doped region is formed at one side of the top silicon, and a first electrode is formed at the upper surface of the first doped region; a coupling layer is formed at the upper surface of the top silicon, an extension portion is formed at one side, back to the first electrode, of the coupling layer, a second doped area is formed by the extension portion, and a second electrode is formed at the second doped area; and the silicon nitride waveguide is a taper structure andis formed at the upper portion of a polycrystalline silicon layer. Through reconstruction of the germanium layer structure, the top silicon and the germanium layer are doped to enhance the coupling efficiency of the silicon n