MULTI-STAGE AVALANCHE PHOTODETECTOR Russian patent published in 2010 - IPC H01L31/72 

FIELD: physics.

SUBSTANCE: multi-stage avalanche photodetector has at least two multiplication stages based on semiconductor p⁺-n (n⁺-p) heterostructures, including at least two semiconductor layers. Thickness of the first layers of the heterostructures does not exceed the diffusion length of minority carriers. Concentration of doping impurities in the first layers of the heterostructures exceeds concentration of the doping impurities in the second layers. In each first layer of the structures and the second layer of the last structure there are ohmic contacts. The band gap of the first layers of the heterostructures is less than the band gap of the second layers. The band gap of the first layer of the first heterostructure does not exceed the band gap of the first layers of the rest of the heterostructures and second layers of the heterostructures have the same band gap.

EFFECT: increased multiplication factor and signal-to-noise ratio of the photodetector with simultaneous expansion of the spectral range of photosensitivity in the long-wave range, maintenance of operating temperature and suppression of parasitic photosensitivity.

8 cl, 6 dwg